Shortness of breath in cancer: causes, diagnosis, treatment, and warning signs

Shortness of breath in cancer is a sensation of shortness of breath, difficulty in inhaling, an inability to "get enough air," chest tightness, or unusually heavy breathing during exertion or at rest. In oncology, this symptom is called one of the cardiopulmonary syndromes because it can be related to the lungs, heart, blood, tumor, treatment, and overall health. [1]

Shortness of breath is not a separate diagnosis. It is a symptom that can occur with lung cancer, lung metastases, pleural effusion, pericardial effusion, pulmonary embolism, anemia, infection, respiratory muscle weakness, anxiety, pain, treatment side effects, and concomitant heart or lung disease. [2]

It's important to understand that the severity of shortness of breath doesn't always correspond precisely to the tumor size. In one patient, a small amount of fluid around the lung may cause severe shortness of breath, while in another, large changes on the image may cause moderate symptoms if they develop slowly and the body has time to adapt. [3]

Shortness of breath may be sudden or progressive. Sudden shortness of breath, especially with chest pain, hemoptysis, severe weakness, fainting, or palpitations, requires urgent medical attention because pulmonary embolism, pneumothorax, severe infection, cardiac tamponade, or rapid deterioration of respiratory function may occur. [4]

Current guidelines recommend a hierarchical approach: first assess the severity of dyspnea, then find and treat reversible causes, and if the cause cannot be completely eliminated, add symptom relief methods, including body position, airflow, breathing techniques, physical rehabilitation, psycho-emotional support, and medications as indicated. [5]

Question	Short answer
What is shortness of breath?	Feeling short of breath or having difficulty breathing
Is this always a sign of cancer progression?	No, the cause may be reversible.
What are the most dangerous causes?	Pulmonary embolism, infection, pericardial effusion, severe anemia, airway compression
Should I tolerate shortness of breath?	No, the symptom needs to be reported to the doctor.
What is treated first?	The cause of shortness of breath
What to do if the cause cannot be completely eliminated	Alleviate symptoms and improve quality of life

Source for the table: US National Cancer Institute, American Society of Clinical Oncology, European Society for Medical Oncology. [6] [7] [8]

Why does shortness of breath occur with cancer?

The most obvious cause is lung damage from the tumor itself. Lung cancer, lung metastases, tumor-induced bronchial narrowing, or tumor spread through the pulmonary lymphatics can reduce the working surface area of the lungs, impair ventilation, and cause a feeling of shortness of breath. [9]

The second common cause is fluid around the lung, known as pleural effusion. In malignant pleural effusion, fluid accumulates between the lung and the chest wall, compressing the lung and preventing it from fully expanding. This can cause chest heaviness, shortness of breath, coughing, and difficulty breathing when lying down. [10]

The third cause is problems with the heart and blood vessels. Malignant pericardial effusion can compress the heart and prevent it from pumping blood properly; pulmonary embolism occurs when a blood clot blocks the blood vessels in the lungs and can present with sudden shortness of breath, chest pain, hemoptysis, palpitations, or fainting. [11] [12]

The fourth cause is a decrease in the blood's ability to carry oxygen. With anemia, hemoglobin levels decrease, tissues receive less oxygen, and the patient may experience weakness, palpitations, dizziness, and shortness of breath even with minimal exertion. [13]

The fifth reason is cancer treatment. Chest radiation therapy, some types of chemotherapy, immunotherapy, targeted therapy, surgery, pain medications, infections associated with decreased immunity, and general muscle loss can directly or indirectly impair breathing. [14]

Cause	How does shortness of breath occur?	What may accompany
Tumor in the lung	Closes a bronchus or reduces the functioning of lung tissue	Cough, chest pain, blood in sputum
Lung metastases	They disrupt gas exchange and elasticity of the lungs	Fatigue, cough, decreased activity
Pleural effusion	Compresses the lung from the outside	Heaviness in the chest, worse when lying down
Pericardial effusion	It squeezes the heart	Shortness of breath when lying down, weakness, rapid pulse
Pulmonary embolism	Blocks blood flow to the lungs	Sudden shortness of breath, pain, hemoptysis
Anemia	Reduces oxygen delivery to tissues	Weakness, palpitations, dizziness
Cancer treatment	Inflammation, toxicity, infection, muscle weakness	Depends on the treatment method

Source for the table: National Cancer Institute USA, Cancer Research UK, American Cancer Society. [15] [16] [17]

How does a person feel shortness of breath?

Patients describe shortness of breath in various ways: "not enough air," "hard to breathe," "can't take a full breath," "chest tightness," "breathing rapidly," "out of breath when walking," "can't lie still," "feels like air can't get through." These descriptions are important because different sensations can suggest different causes. [18]

Shortness of breath during exertion often appears earlier than shortness of breath at rest. Initially, a person notices that they have difficulty stopping on stairs, walking more slowly, and are unable to carry groceries or talk while walking. Later, breathing may become labored even when dressing, washing, or talking. [19]

Dyspnea lying down is especially important. If a person feels better while sitting, but shortness of breath occurs while lying down, this may be due to pleural effusion, heart failure, pericardial effusion, a large abdomen due to ascites, or respiratory muscle weakness. [20]

Shortness of breath often increases anxiety, and anxiety increases shortness of breath. This doesn't mean the symptom is "psychological" or "imaginary": when short of breath, the brain perceives the situation as a threat, triggers a stress response, and increases breathing and heart rate, which can perpetuate a cycle of fear and suffocation. [21]

Dyspnea should be assessed not only by blood oxygen saturation. Some patients may experience significant subjective difficulty breathing even with normal oxygen saturation, while others may experience a less pronounced decrease in oxygen. Therefore, the physician considers complaints, physical examination, respiratory rate, pulse, laboratory tests, and imaging data. [22]

As the patient describes	Possible clue
"I get out of breath when I walk"	Decreased pulmonary reserve, anemia, weakness, cardiac cause
"I can't lie down"	Pleural effusion, pericardial effusion, heart, ascites
"Suddenly I couldn't breathe."	Pulmonary embolism, pneumothorax, acute infection
"There's a pressure in my chest"	Heart, pleura, tumor, anxiety, thromboembolism
"Cough and shortness of breath"	Lungs, bronchi, infection, treatment
Shortness of breath and palpitations	Anemia, thromboembolism, anxiety, heart
"Shortness of breath after a course of treatment"	Side effects of therapy, infection, anemia, pneumonia

Source for the table: National Cancer Institute of the USA, Cancer Research UK, European Society for Medical Oncology. [23] [24] [25]

Dangerous Causes of Shortness of Breath That You Shouldn't Ignore

Pulmonary embolism is one of the most dangerous causes of sudden shortness of breath in cancer patients. Cancer and certain treatments increase the risk of blood clots, and a clot in the pulmonary artery can cause sudden shortness of breath, chest pain when inhaling, coughing up blood, weakness, fainting, or a rapid heartbeat. [26]

Malignant pleural effusion can develop gradually or rapidly. If the fluid compresses the lung, the person often complains of shortness of breath when walking, chest tightness, a dry cough, and an inability to lie comfortably on one side. [27]

Pericardial effusion and cardiac tamponade require special attention. The National Cancer Institute notes that fluid around the heart can cause shortness of breath, cough, chest pain or pressure, difficulty breathing when lying down, rapid heartbeat, weakness, and fainting; in the case of cardiac tamponade, the situation can be life-threatening. [28]

Superior vena cava syndrome occurs when a tumor or enlarged lymph nodes block blood flow from the head, neck, upper chest, and arms. Symptoms may include shortness of breath, swelling of the face and neck, a feeling of fullness, varicose veins in the chest, cough, headache, and worsening pain when bending over or lying down. [29]

Lung infection in a patient with cancer can progress more rapidly and be more severe, especially after chemotherapy, with low white blood cell counts, after surgery, with tumor-induced bronchial narrowing, or in a weakened state. Shortness of breath with high fever, chills, confusion, a drop in blood pressure, or severe weakness requires urgent evaluation. [30]

Dangerous cause	Typical signs	Why is it urgent?
Pulmonary embolism	Sudden shortness of breath, pain when inhaling, blood in the sputum, fainting	It can be life-threatening.
Pleural effusion	Increasing shortness of breath, heaviness in the chest, dry cough	The lung is compressed by fluid
Pericardial effusion	Shortness of breath when lying down, chest pressure, weakness, rapid pulse	Cardiac tamponade is possible
Superior vena cava syndrome	Swelling of the face and neck, shortness of breath, dilated veins	Venous outflow is impaired
Pneumonia	Shortness of breath, fever, cough, weakness	Risk of severe infection
Pneumothorax	Sudden pain and shortness of breath	The lung partially collapses
Severe anemia	Shortness of breath, palpitations, weakness, dizziness	Tissues receive little oxygen

Source for the table: US National Cancer Institute, Cancer Research UK, US National Cancer Institute dictionary. [31] [32] [33]

Shortness of breath in different types of cancer

In lung cancer, shortness of breath may be due to a tumor in the bronchus, inflammation around the tumor, atelectasis, pleural effusion, hemoptysis, infection, chronic lung disease in a smoker, or the effects of treatment. The American Cancer Society notes that symptoms of lung cancer may include a cough that persists or worsens, blood in the sputum, chest pain, hoarseness, weight loss, shortness of breath, and recurrent infections. [34]

In breast cancer, shortness of breath may occur not due to the primary tumor itself, but due to metastases to the lungs or pleura, pleural effusion, anemia, thrombosis, treatment side effects, or heart disease. In some patients, chest treatment requires monitoring of the heart and lungs, especially if risk factors are present. [35]

In lymphomas, shortness of breath may be associated with enlarged thoracic lymph nodes, pleural effusion, pericardial effusion, anemia, infection, or superior vena cava syndrome. If shortness of breath is associated with night sweats, fever, weight loss, and enlarged lymph nodes, this requires investigation. [36]

In tumors of the stomach, intestines, pancreas, liver, and ovaries, shortness of breath can occur due to ascites, anemia, weakness, thrombosis, lung metastases, or pleural effusion. Extensive ascites elevates the diaphragm, reduces inspiratory volume, and can produce a feeling of heaviness and shortness of breath even without primary lung disease. [37]

In advanced cancer, anywhere, dyspnea is often multifactorial: tumor, muscle weakness, anemia, decreased physical activity, anxiety, pain, infection, cachexia, and treatment side effects can all be simultaneously present. Therefore, guidelines emphasize the need to not automatically look for a single cause, but to conduct a systemic assessment. [38]

Type of cancer or situation	Possible mechanisms of dyspnea
Lung cancer	Tumor in the bronchus, pleural effusion, infection, chronic lung disease
Lung metastases	Impaired gas exchange, cough, decreased respiratory reserve
Lymphoma	Chest nodules, anemia, pleural or pericardial effusion
Breast cancer	Metastases, pleural effusion, treatment, anemia, thrombosis
Liver and gastrointestinal cancer	Ascites, anemia, weakness, thrombosis
Ovarian cancer	Ascites, pleural effusion, anemia, thrombosis
widespread cancer	A combination of several reasons

Source for the table: National Cancer Institute of the United States, American Cancer Society, Cancer Research UK. [39] [40] [41]

How a doctor examines a patient with shortness of breath

Diagnosis begins with an assessment of urgency. The doctor or medical team will determine whether shortness of breath developed suddenly or gradually, whether there is chest pain, fever, cough, blood in the sputum, wheezing, leg swelling, weakness, fainting, rapid heartbeat, and whether it is related to body position. [42]

An examination is then performed: they measure the respiratory rate, pulse, blood pressure, temperature, blood oxygen saturation, listen to the lungs and heart, assess swelling, skin color, venous distension, signs of infection, dehydration, pain and anxiety. [43]

Basic tests often include a complete blood count, biochemical parameters, inflammatory markers, renal and liver function tests, and, if infection or thrombosis is suspected, additional tests based on the clinical situation. Anemia, infection, electrolyte disturbances, and drug toxicity can be reversible causes of dyspnea.[44]

Instrumental studies are selected based on the probable cause. These may include chest X-ray, computed tomography, computed tomography with contrast of the pulmonary arteries if thromboembolism is suspected, pleural ultrasound, echocardiography, electrocardiogram, spirometry, and bronchoscopy as indicated. [45]

It is important to assess not only the cause but also the severity of the symptom for the patient. Guidelines from the American Society of Clinical Oncology and the European Society for Medical Oncology emphasize that dyspnea should be measured, monitored over time, and its impact on sleep, the ability to walk, talk, eat, care for oneself, and tolerate treatment should be considered. [46] [47]

Diagnostic stage	What do they check?	For what
Urgency assessment	Sudden onset, pain, blood, fainting, fever	Don't miss a dangerous situation
Inspection	Respiratory rate, pulse, blood pressure, temperature, oxygen saturation	Assess the severity
Blood tests	Hemoglobin, leukocytes, inflammation, biochemistry	Find anemia, infection, metabolic disorders
Chest X-ray	Lungs, fluid, infection, tumor changes	Rapid initial assessment
Computed tomography	Detailed assessment of the lungs and blood vessels	Suspected thrombosis, tumor, complications
Echocardiography	The heart and fluid around the heart	Suspected pericardial effusion
Ultrasound of the pleura	Fluid around the lung	Planning a puncture or drainage

Source for the table: US National Cancer Institute, American Society of Clinical Oncology, European Society for Medical Oncology. [48] [49] [50]

Treatment of the cause of shortness of breath

If shortness of breath is caused by a pleural effusion, the doctor may suggest removing the fluid through a thoracentesis, chest tube placement, pleurodesis, or an indwelling pleural catheter. The choice depends on the rate of fluid accumulation, the patient's overall condition, prognosis, lung re-expansion, and treatment goals. [51]

If the cause is pericardial effusion, treatment may include echocardiographic monitoring, pericardiocentesis, drainage, and treatment of the underlying tumor. In cardiac tamponade, fluid removal is performed urgently because the heart cannot fill and pump blood normally. [52]

If pulmonary embolism or deep vein thrombosis is detected, anticoagulant treatment is usually prescribed, but in patients with cancer, the risk of bleeding, tumor type, renal function, platelets, drug interactions and the need for procedures are always assessed.[53]

If shortness of breath is due to an infection, treatment may include antibiotics, antifungal, or antiviral medications as indicated, oxygen, fluids, temperature control, and sometimes hospitalization. In patients undergoing chemotherapy, infection can be dangerous even with mild initial symptoms.[54]

If anemia is the cause, treatment depends on the hemoglobin level, symptoms, the cause of the anemia, the type of cancer, and current treatment. The doctor may consider bleeding management, correction of deficiencies, changes in therapy, red blood cell transfusions, or other measures, but the choice is always individual. [55]

Cause	Possible treatment
Pleural effusion	Puncture, drainage, pleurodesis, pleural catheter
Pericardial effusion	Echocardiography, pericardiocentesis, drainage
Pulmonary embolism	Anticoagulants and bleeding risk assessment
Infection	Antimicrobial treatment, oxygen, observation
Anemia	Search for the cause, correction of deficiency, transfusion as indicated
Bronchial compression	Radiation therapy, bronchoscopic intervention, stent as indicated
Ascites	Treatment of the cause, ascites puncture, supportive therapy

Source for the table: National Cancer Institute of the USA, European Society for Medical Oncology, Cancer Research UK. [56] [57] [58]

Symptomatic treatment of shortness of breath

Even when the underlying cause is already treated, patients often need help with the sensation of shortness of breath itself. The American Society of Clinical Oncology recommends starting with assessing and treating reversible causes, then using non-drug and drug-based symptom relief approaches depending on the severity and context. [59]

Simple measures can be very helpful: sitting with your arms supported, cool air flowing over your face, an open window, a fan, calm, slow breathing, relaxing your shoulders, conserving energy, and planning activities with pauses. The European Society for Medical Oncology includes non-pharmacological approaches as an important part of managing dyspnea in patients with cancer. [60]

Oxygen doesn't help everyone. If a patient has low blood oxygen saturation, oxygen therapy may be necessary; if saturation is normal, shortness of breath is sometimes better reduced by airflow, breathing techniques, anxiety treatment, opioids when indicated, and control of the underlying cause, rather than oxygen alone. [61]

Opioids may be used for severe, persistent shortness of breath in patients with advanced cancer, especially when reversible causes have been eliminated or are irreversible. This does not mean "treatment only at the end of life": in palliative care, low doses of opioids can reduce the distressing sensation of shortness of breath, but require physician selection and monitoring. [62]

Anxiety, panic, and fear of suffocation require specific care. Patients can benefit from an explanation of the mechanism of shortness of breath, the presence of a loved one, breathing techniques, psychological support, pain and insomnia treatment, and, in some cases, anti-anxiety medications, as strictly indicated. [63]

Method of relief	When is it useful?	Important clarification
Sitting position with support	For shortness of breath at rest and after exercise	Reduces the work of breathing
Air flow on the face	In case of subjective shortness of breath	It can help even without reducing oxygen.
Breathing techniques	For anxiety and shortness of breath due to exertion	It's better to study in advance
Oxygen	When oxygen saturation decreases	Doesn't always help with normal saturation
Opioids	For severe, persistent shortness of breath	Only by doctor's prescription
Rehabilitation	In case of weakness and decreased load	Selected individually
Psychological support	For fear of suffocation	Reduces anxiety and shortness of breath

Source for the table: American Society of Clinical Oncology, European Society for Medical Oncology, Cancer Research UK. [64] [65] [66]

What can you do at home if you already have shortness of breath?

If a doctor has already assessed shortness of breath and ruled out urgent causes, it is helpful to organize the space at home to reduce the load: keep necessary things close by, sit while washing and dressing, take breaks, take your time after eating, use handrails, and avoid unnecessary climbing stairs. [67]

Posture matters. Many people find it easier to sit, leaning slightly forward with their elbows resting on their knees or a table; this position helps engage the accessory muscles of breathing and reduces the feeling of struggling to breathe. [68]

Breathing techniques are best mastered before a severe attack. Typical techniques include slow inhalation through the nose, long exhalations through slightly pursed lips, relaxed shoulders, counting breaths, and resting to recover after exertion. Specific techniques are best developed with the help of a physical therapist or palliative care team. [69]

An attack of shortness of breath is often frightening, so it is helpful to have a pre-written plan: what position to assume, who to call, what medications the doctor has approved, when to turn on oxygen, when to call an ambulance, and what symptoms are considered dangerous. [70]

It is important not to use oxygen, inhalers, sedatives, or opioids without a doctor's prescription. Inappropriate use may mask deterioration, cause side effects, or delay treatment for thromboembolism, infection, pericardial effusion, or other urgent causes. [71]

Home measure	How it helps
Sit while washing and dressing	Saves energy
Take pauses between actions	Prevents attacks of shortness of breath
Use a fan or cool air	Reduces the feeling of shortness of breath
Forward Bend Pose	Reduces the work of breathing
A long, calm exhalation	Helps with panic and shallow breathing
Action plan for an attack	Reduces fear and speeds up help
Shortness of breath diary	Helps the doctor assess the dynamics

Source for table: Cancer Research UK, European Society for Medical Oncology, American Society of Clinical Oncology. [72] [73] [74]

When urgent help is needed

You should seek immediate medical attention if shortness of breath appears suddenly, rapidly worsens, occurs at rest, or is accompanied by chest pain, coughing up blood, fainting, palpitations, blue lips, confusion, or severe weakness. [75]

Prompt help is needed for shortness of breath with a high fever, chills, wet cough, a drop in blood pressure, or severe weakness, especially if the patient is receiving chemotherapy, has recently had surgery, or has a weakened immune system. [76]

Urgent evaluation is necessary if you experience difficulty breathing while lying down, swelling of the face and neck, a feeling of fullness in the head, dilated veins in the chest, or severe pressure in the upper chest. This may indicate pericardial effusion or superior vena cava syndrome. [77]

Shortness of breath with pain or swelling in one leg, sudden chest pain, and hemoptysis are particularly suggestive of pulmonary embolism and thrombosis. These conditions are more common in cancer patients than in the general population and require prompt diagnosis and treatment. [78]

If shortness of breath gradually worsens but interferes with speaking, eating, sleeping, walking, or performing routine personal care, there's no need to wait for a scheduled visit in a few weeks. Even if the cause isn't immediately life-threatening, the symptom requires treatment because it significantly impairs quality of life and treatment tolerance. [79]

Symptom	Possible cause	Tactics
Sudden shortness of breath	Thromboembolism, pneumothorax, acute cardiac or pulmonary cause	Urgently
Shortness of breath plus chest pain	Thromboembolism, heart, pleura	Urgently
Shortness of breath plus blood in sputum	Thromboembolism, tumor, infection	Urgently
Shortness of breath plus high fever	Pneumonia, sepsis, neutropenia	Urgently
Shortness of breath when lying down	Heart, pericardium, pleura, ascites	Quick assessment
Swelling of the face and neck	Superior vena cava syndrome	Urgently
Shortness of breath makes it difficult to speak	Severe respiratory failure	Urgently

Source for the table: Cancer Research UK, National Cancer Institute USA, European Society of Cardiology. [80] [81] [82]

Prognosis and quality of life

The prognosis for dyspnea depends not on the word "dyspnea" itself, but on the underlying cause. Whether the symptom is caused by anemia, infection, effusion, thromboembolism, bronchospasm, or a side effect of treatment, some causes can be treated aggressively and provide significant relief. [83]

With advanced cancer, shortness of breath is often chronic and multifactorial, but this doesn't mean help is impossible. Modern palliative care focuses not only on the last days of life, but also on improving breathing, sleep, activity, anxiety, pain control, and the patient's ability to live as fully as possible in their situation. [84]

Early palliative care is especially important if shortness of breath recurrs, becomes a major limiting symptom, triggers panic attacks, or interferes with treatment. The team can assist with breathing techniques, medications, home care, equipment, psychological support, and a plan for action in the event of deterioration. [85]

Supervised physical activity can improve exercise tolerance in some patients, but it must be done safely. In cases of severe anemia, unstable shortness of breath, suspected thromboembolism, uncontrolled pain, high fever, or severe weakness, exercise should first be discussed with a physician. [86]

The main practical conclusion: shortness of breath in cancer cannot be considered inevitable and incurable. Even if the tumor cannot be completely eliminated, the symptom can often be alleviated, and if the cause is reversible, timely diagnosis can significantly improve the patient's well-being and safety. [87]

Situation	What influences the prognosis?
Reversible cause	Rapid diagnosis and treatment
Pleural effusion	Fluid accumulation rate and drainage capability
Thromboembolism	Timeliness of anticoagulant treatment and the risk of bleeding
Anemia	Cause of anemia and response to correction
widespread cancer	Symptom control and supportive care
Anxiety and panic	Training, action plan, psychological support
Weakness and muscle loss	Rehabilitation, nutrition, disease control

Source for the table: National Cancer Institute, American Society of Clinical Oncology, European Society for Medical Oncology. [88] [89] [90]

FAQ

Does shortness of breath in cancer always mean lung metastases? No. Shortness of breath can be associated with lung metastases, but it can also be associated with anemia, pleural effusion, thromboembolism, infection, pericardial effusion, ascites, weakness, anxiety, concomitant heart and lung disease, or treatment side effects. [91]

What type of shortness of breath is most dangerous? The most worrisome is sudden shortness of breath, especially if accompanied by chest pain, blood in the sputum, fainting, rapid heartbeat, blue lips, confusion, or severe weakness. This requires urgent evaluation because a pulmonary embolism or other dangerous condition is possible. [92]

Do all patients with shortness of breath need oxygen? No. Oxygen is especially important when blood oxygen saturation is low, but when saturation is normal, subjective shortness of breath is sometimes better reduced by airflow to the face, body position, breathing techniques, anxiety management, and other methods. [93]

Can shortness of breath be caused by anemia? Yes. With anemia, the blood carries less oxygen, causing weakness, palpitations, dizziness, and shortness of breath during exercise or at rest. In cancer patients, anemia can be related to the tumor, bleeding, deficiencies, inflammation, or treatment. [94]

Why does shortness of breath worsen at night or when lying down with cancer? This can occur with pleural effusion, pericardial effusion, heart failure, ascites, anxiety, respiratory muscle weakness, or secretions in the airways. If breathing becomes noticeably more difficult when lying down, you should tell your doctor. [95]

Can shortness of breath develop after radiation therapy or chemotherapy? Yes. Treatment can cause lung inflammation, infectious complications, anemia, weakness, and cardiac and pulmonary side effects, so new shortness of breath after treatment requires evaluation and not automatically dismissed as "normal weakness." [96]

What should you do during an attack of shortness of breath at home? If there are no signs of immediate danger and your doctor has already given you a plan, you should sit up, lean forward slightly, support yourself with your hands, turn on a cool stream of air to your face, exhale slowly through slightly closed lips, and use the prescribed medications. If shortness of breath is new, severe, or rapidly worsening, seek immediate help. [97]

Can you take sedatives for shortness of breath? Only with a doctor's prescription. Anxiety can indeed worsen shortness of breath, but sedatives can depress breathing, interact with painkillers, and mask a dangerous worsening. [98]

When does shortness of breath require hospitalization? Hospitalization may be necessary if breathing deteriorates sharply, oxygen levels decrease, thromboembolism, pneumonia, cardiac tamponade, pneumothorax, severe anemia, sepsis, or the inability to control the symptom at home are suspected. [99]

Is it possible to completely eliminate shortness of breath due to cancer? Sometimes yes, if the cause is reversible, such as anemia, effusion, infection, or thrombosis. If the cause is related to a widespread tumor and cannot be completely eliminated, the goal of treatment is to minimize shortness of breath, anxiety, activity limitations, and improve quality of life. [100]

Key points from experts

David Hui, MD, MS, professor and director of supportive and palliative care research at The University of Texas MD Anderson Cancer Center. In the American Society of Clinical Oncology guideline for dyspnea in advanced cancer, he and an expert panel recommend a hierarchical approach: assess the symptom, find and treat reversible causes, then use non-pharmacological and pharmacological therapies for relief. [101] [102]

Margaret L. Campbell, PhD, RN, Wayne State University, is co-chair of the American Society of Clinical Oncology expert panel. As part of the guideline on dyspnea in advanced cancer, she helped formulate a practical approach in which symptom assessment and treatment of the cause come before prescribing symptomatic medications. [103]

Experts from the European Society for Medical Oncology, in a clinical guideline on dyspnea in cancer patients, emphasize that shortness of breath can be associated with tumor progression, treatment, infection, thromboembolism, and comorbidities, so treatment should be comprehensive and individualized. [104]

National Cancer Institute experts. The 2025 update on cardiopulmonary syndromes notes that dyspnea in cancer is often multifactorial, and the diagnostic evaluation should consider tumor, cardiac, pulmonary, infectious, and therapeutic causes. [105]

Cancer Research UK experts. Patient information stresses that breathlessness in cancer can be caused by the tumour itself, treatment or other conditions, and treatment depends on the cause; sudden, worsening or painful breathlessness requires immediate contact with healthcare services. [106]

American Cancer Society experts. In their 2025 update on shortness of breath in cancer, the organization describes shortness of breath as the sensation of not being able to breathe enough air and emphasizes that cancer and its treatments can cause this symptom in a variety of ways. [107]

Result

Shortness of breath in cancer is a common, severe, and sometimes dangerous symptom, but it does not always indicate tumor progression. Causes can be reversible: anemia, infection, pleural effusion, thromboembolism, pericardial effusion, a side effect of treatment, or concomitant heart and lung disease. [108]

The most alarming signs include sudden shortness of breath, chest pain, blood in the sputum, fainting, blue lips, high fever, confusion, swelling of the face and neck, rapid heartbeat, or difficulty speaking due to breathing. These symptoms require immediate medical attention. [109]

The diagnosis is made step by step: assessment of urgency, examination, blood oxygen saturation, blood tests, radiography or CT scan, assessment of the pleura, heart, thrombosis, infection, anemia and side effects of treatment. [110]

Treatment should be causative: removal of fluid in case of effusion, treatment of infection, anticoagulants in case of thrombosis, correction of anemia, treatment of tumor compression, assistance with cardiac complications. If the cause cannot be completely eliminated, methods for relieving dyspnea and palliative support are used. [111]

The main rule for the patient and family: shortness of breath cannot be tolerated in silence and cannot be treated solely with home remedies without understanding the cause. The sooner the symptom is reported to the treatment team, the greater the chance of quickly finding a reversible cause, reducing anxiety, improving breathing, and maintaining the ability to continue treatment. [112]