The female urethra: structure and diseases

The female urethra is a short tube that carries urine from the bladder to the outside. It begins at the neck of the bladder and ends at the external opening in the vestibule of the vagina, between the labia minora. [1]

The urethra performs two key functions. The first is the transport of urine. The second is the retention of urine between urinations, that is, ensuring continence through the coordinated work of the sphincters, the supporting structures of the pelvic floor, and nervous regulation. [2]

From a practical standpoint, the female urethra is important because it is anatomically closely connected to the vagina and anterior pelvic wall. Because of this proximity, inflammation, trauma, surgery, and age-related changes in the vagina and pelvic floor often affect urination and lower urinary tract symptoms. [3]

The female urethra is more often involved in lower urinary tract infections than the male urethra. The main anatomical reasons are its short length and the proximity of the external opening to the perineum, which facilitates the entry of bacteria into the lower urethra and bladder under unfavorable conditions. [4]

Table 1. The female urethra in 6 facts

Fact	The essence	Why is it important?
Length	Usually about 4 cm, range about 3.8-5.1 cm	Affects the risk of ascending infection
Move	Runs along the anterior wall of the vagina	Explains the relationship between urological and gynecological symptoms
External opening	Opens into the vestibule of the vagina	Important for examination and diagnosis of inflammation
Sphincter control	There are smooth muscle and striated components.	Important for urinary retention
Periurethral glands	Paraurethral glands near the distal part	May be involved in inflammation and diverticulum formation
Key clinical topics	Infections, diverticulum, prolapse, stricture, incontinence	These are common reasons for complaints.

The figures and anatomical landmarks are based on modern reviews. [5]

Topography and dimensions: where the urethra passes and what it comes into contact with

The female urethra extends from the neck of the bladder downward and forward, located behind the pubic symphysis. Throughout its length, it is embedded in the anterior wall of the vagina, so pelvic floor movements and the condition of the vaginal tissues influence its position and support. [6]

Externally, the urethra passes through the structures of the pelvic floor and perineum, including the area of the perineal membrane. This is important for understanding postpartum trauma and functional impairment: damage to the supporting structures and nerves can alter the urethral "closure" mechanism. [7]

The typical length of the adult female urethra is most often described as around 4 cm, although various sources report a range of approximately 3-5 cm. This variation is due to measurement methods and individual anatomy, so in the clinic it is better to focus on functional complaints and examination data rather than on the “ideal figure.” [8]

The short length and relatively straight course of the cyst create conditions for the rapid spread of infection to the bladder, especially when the vaginal microflora changes and local defenses are weakened. This is one of the reasons why, with typical symptoms of cystitis in women, the diagnosis is often made clinically, and the examination is selected based on the risk of complications. [9]

Table 2. Topographical landmarks and practical meaning

Landmark	Where is it located?	Practical significance
Neck of the bladder	Proximal start of the urethra	Important for assessing urinary continence
Pubic symphysis	Anterior to the urethra	A guide for visualization and manipulation
Anterior vaginal wall	Close contact throughout	Explains symptoms after childbirth and tissue atrophy
Perineal membrane	In the distal part	Participation in the mechanism of the external sphincter
External opening of the urethra	In the vestibule of the vagina	Examination for pain, burning, discharge

Landmarks and relative positions are summarized from clinical anatomical reviews. [10]

Urethral wall, epithelium and paraurethral glands

The urethral wall consists of a mucous membrane, a submucous layer, and muscular elements. The mucous membrane forms longitudinal folds that help the urethra close at rest and create an additional barrier to microbes.

The urethral epithelium varies along its length. Proximally, urothelium similar to that of the bladder is most common, followed by a possible transition to pseudostratified columnar epithelium, while distally, stratified squamous nonkeratinizing epithelium predominates. This transition is important for understanding the symptoms of irritation and for interpreting inflammatory and precancerous changes. [12]

Located within the wall and around the distal portion are the paraurethral glands, often called Skene's glands. Their ducts open near the external opening of the urethra, and when inflamed, these glands can become a source of localized pain and swelling. [13]

From a clinical perspective, the paraurethral glands are also important because chronic inflammation of the periurethral glands is considered one of the mechanisms for the formation of urethral diverticula in women. This explains why diverticula are often associated with recurrent infections and "unexplained" urological complaints. [14]

Table 3. Urethral zones and epithelial type

Plot	The most common type of epithelium	Clinical clue
Proximal	Urothelium	Reacts to inflammation similar to cystitis
Average	Pseudo-multilayer cylindrical often	Transition zone, variability
Distal	Multilayered flat non-keratinizing	More often involved in local irritation and trauma
Periurethral zone	Skene's gland ducts	Local inflammation and cysts are possible

Data on the epithelium and glands are provided from histological and clinical sources. [15]

Sphincters and urinary continence: smooth muscle, striated sphincter, and pelvic floor

Urinary continence is achieved through a combination of anatomy and neural regulation. Proximally, the urethra is connected to the smooth muscle zone at the bladder neck, which is functionally involved in "internal" closure. This mechanism is particularly important for maintaining closure pressure at rest. [16]

Primary voluntary control is associated with the striated external sphincter complex. Modern anatomical sources emphasize that in women, this sphincter is often constructed as a semicircle or omega-shaped structure and may not completely encircle the urethra. This helps explain why pelvic floor weakness after childbirth and with age so significantly affects stress urinary incontinence. [17]

The external sphincter complex includes several components, which are distinguished separately in various anatomical descriptions: the urethral compressor and the urethrovaginal sphincter. Their contraction increases outflow resistance and simultaneously supports the anterior vaginal wall, so dysfunction can manifest as both urological and gynecological complaints. [18]

The sphincters work in conjunction with the supporting structures of the pelvic floor and connective tissue. When coughing, running, and lifting heavy objects, abdominal pressure increases, and the urethra must "support" this pressure to prevent leakage. If this support is weakened, symptoms of stress urinary incontinence occur, especially during exertion. [19]

Table 4. The sphincter complex in women: what it consists of

Component	Fabric type	Where is it located?	What does it do?
Smooth muscle component in the cervical region	Smooth muscle	Proximally	Resting, participating in closing
External striated sphincter	Striated muscle	The distal 2 thirds of the urethra in many women	Arbitrary control
Urethral compressor	Striated muscle	Anteriorly and laterally	Compression of the urethra during straining
Urethrovaginal sphincter	Striated muscle	Covers the urethra and vagina	Joint "closure" and support

The components and their descriptions are given according to modern anatomical reviews. [20]

Blood supply, innervation and lymphatic drainage

The blood supply to the urethra in women is provided by branches of the internal genital and vaginal arteries, as well as branches associated with the bladder. Good blood supply is important for healing after injury and surgery, but during inflammation, it also contributes to severe swelling and pain. [21]

Venous drainage typically follows the arteries, forming vascular plexuses in the pelvic region. This is of practical importance during interventions, as even minor manipulations in the periurethral area can be accompanied by bleeding in some patients. [22]

Innervation includes autonomic pathways from the vesical plexus and somatic innervation via the pudendal nerve. Autonomic fibers are involved in urge sensation and smooth muscle regulation, while somatic fibers provide voluntary control of the external sphincter. [23]

Lymphatic drainage from the urethra is important in tumor diseases, although primary cancer of the female urethra is rare. If a tumor is suspected, local spread and regional lymph nodes are assessed, as this influences the staging and treatment plan. [24]

Table 5. Nerves and vessels: a brief map

System	Main sources	What does it provide?	Clinical clue
Arteries	Internal genital, vaginal and associated branches	Blood supply to the mucous membrane and muscles	Important for healing and swelling during inflammation
Vienna	The eponymous venous pathways of the pelvis	Venous outflow	Bleeding may occur during manipulation.
Autonomic nerves	Vesicular plexus, pelvic splanchnic nerves	Urges, smooth muscle function	Symptoms may be "vegetative"
Somatic nerves	Pudendal nerve	Voluntary sphincter control	Important for stress incontinence
Lymph	Pelvic lymphatic collectors	Immune drainage, tumor pathways	Important in rare urethral tumors

Data on the sources of blood supply and innervation are summarized from anatomical reviews. [25]

Age and individual characteristics that change symptoms

With age, not only hormonal levels but also the mucous membranes of the urethra and vagina change. At the epithelial level, a tendency toward a gradual shift toward more pronounced flat and metaplastic changes has been described in some women, which affects the sensation of dryness, burning, and vulnerability to microtrauma. [26]

The urethra in children and adolescents differs in size and maturity of the sphincter apparatus. During childhood, the striated sphincter and neuromuscular control continue to develop, so some urinary symptoms and disorders in childhood differ in nature from those in adults.

Individual variations in the structure of the periurethral glands and soft tissues around the external opening may explain why some women experience recurrent local inflammation under identical conditions, while others do not. This is not due to "poor hygiene," but to a combination of anatomy, microbiota, and risk factors. [28]

A separate group of options relates to pelvic floor support. Childbirth, injuries, and age alter the position of the urethra and its angle relative to the bladder, increasing the likelihood of stress urinary incontinence. These changes often occur in conjunction with pelvic organ prolapse, so the complaints are usually complex. [29]

Diseases of the female urethra and why symptoms can be similar

The most common clinical problem is lower urinary tract inflammation, which manifests as burning during urination, frequent urination, and suprapubic discomfort. An anatomically short urethra increases the risk of ascending infection, so risk factor assessment and preventive strategies are important in the event of recurrence. [30]

Urethral diverticulum in women often presents with fluctuating symptoms, including recurrent infections, pain, dysuria, incontinence, discomfort during intercourse, and sometimes blood in the urine. Diagnosis relies on imaging, with magnetic resonance imaging often considered the most informative method for anatomical assessment of the diverticulum, while transvaginal ultrasound and other ultrasound approaches are used as alternatives and adjuncts. [31]

Strictures in the female urethra are less common than in males, but can cause difficulty urinating, a weak stream, straining, a feeling of incomplete urination, and recurrent infections. The underlying mechanism is scar tissue following trauma, inflammation, or surgery, so careful diagnosis is important to distinguish stricture from functional disorders. [32]

Benign lesions of the external orifice, such as a urethral caruncle in postmenopausal women, often present with localized tenderness, bleeding, and a "nodule" at the orifice. Although such lesions are often benign, if they are atypical, rapidly growing, or ulcerated, an in-person evaluation is required to rule out a tumor. [33]

Primary female urethral cancer is rare but clinically significant due to delayed diagnosis. Bleeding, masses, pain, obstructive symptoms, and enlarged inguinal lymph nodes may occur. If suspected, urethrocystoscopy, biopsy, and imaging-guided staging are performed. [34]

Table 6. Symptom and most likely causes

Symptom	The most common causes	What is particularly alarming
Burning sensation when urinating, frequent urge to urinate	Acute cystitis, urethritis	Fever, pain in the side, blood in the urine
Recurrent infections and pain in the urethra	Urethral diverticulum, chronic urethritis	Palpable formation on the anterior vaginal wall
Weak stream, straining	Urethral stricture, pelvic floor dysfunction	Residual urine, urinary retention
Leakage when coughing and running	Stress urinary incontinence	Rapid progression after injury
Bleeding and a nodule at the external opening	Caruncle, inflammation	Ulceration, rapid growth, tight fixation

Symptom profiles are summarized from clinical reviews and case series. [35]

When to see a doctor, diagnosis and prevention

A doctor should be consulted if pain and burning persist for more than 2-3 days, blood in the urine, fever, flank pain, or any new growth in the area of the external urethral opening is present. These signs are important to rule out complicated infection, stones, tumors, and obstruction. [36]

Diagnosis typically begins with simple steps: collecting complaints, assessing risk factors, performing a urinalysis, and, if necessary, urine culture. The choice of methods then depends on the scenario: if a diverticulum is suspected, magnetic resonance imaging and ultrasound are considered; if a stricture or tumor is suspected, endoscopy and biopsy are added. [37]

For recurrent infections, assessment of behavioral factors and evidence-based preventive measures are important. European guidelines on urological infections describe approaches to diagnosis and prevention, including principles for the management of uncomplicated cystitis and strategies for recurrence, with individualization based on the risk of complications. [38]

Prevention includes adequate fluid intake, timely bladder emptying, reducing irritants, careful grooming of the intimate area, and treating conditions that contribute to inflammation. For symptoms of mucosal atrophy after menopause, treatment should be discussed individually with a specialist, as dryness and microtrauma can exacerbate urinary complaints. [39]

Table 7. Step-by-step diagnostics for complaints from the urethra

Step	What are they doing?	For what
1	Examination, collection of symptoms and risk factors	Divide infection, trauma, obstruction, tumor
2	General urine analysis	Assess inflammation and blood
3	Urine culture when indicated	Select therapy for infection and relapses
4	Ultrasound examination, if necessary	Eliminate residual urine, assess periurethral structures
5	Magnetic resonance imaging in suspected diverticulum and complex cases	Accurately describe the anatomy and treatment plan
6	Urethrocystoscopy and biopsy if a tumor or stricture is suspected	Confirm the diagnosis and choose the tactics

The algorithm is based on clinical reviews of diverticula and infections and data on urethral tumors.[40]