Glass test: localization of inflammation in urine portions

A glass test is a step-by-step urine collection in 2, 3, or 4 containers during a single urination, or in combination with prostate massage. Its purpose isn't simply to confirm the presence of inflammation or blood, but to try to understand where exactly the cells, bacteria, or blood are coming from and what part of the genitourinary tract is most likely the source of the problem. Therefore, the glass test is primarily a localization test, not a standard urinalysis.

Today, two large groups of methods are used under this name. The first is urological localization tests in men with suspected chronic bacterial prostatitis. Here, the historical standard is the 4-glass Mears-Stamey test, while a simpler clinical alternative is the 2-glass pre- and post-massage test. The second group is the 3-glass test for visible hematuria, where the distribution of blood along the urination route is used to roughly estimate the likely site of bleeding. [2]

The main practical error is that the glass test is sometimes perceived as a universal test "for the urethra, bladder, and prostate at once." In modern medicine, this is no longer the case. Risk-based algorithms are used for microhematuria. For urethritis, the first portion of urine is, in most cases, more important for molecular testing for chlamydia and gonococcal infections. Prostate massage is generally contraindicated for acute prostatitis. Consequently, the glass test has retained its niche, but this niche has become much narrower than it was 20-30 years ago. [3]

It's especially important to distinguish between the two-glass "before and after massage" test and the usual split urine stream. In urology, a two-glass test for prostatitis refers specifically to a comparison of urine before and immediately after prostate massage. This is not the same as simply collecting the beginning and end of urination. Diagnostic value only arises when there is a prostatic massage step between the two samples, which flushes the contents of the prostatic acini and ducts into the urethra. [4]

Therefore, a modern article on the cup test should be structured not around the question of "how many cups to collect," but around the question of "what clinical problem does this scheme solve?" When it comes to chronic bacterial prostatitis, the 2- and 4-cup tests still appear in European recommendations. When it comes to hematuria, the test remains a guideline but does not replace cystoscopy and imaging. If a sexually transmitted infection is suspected, priority shifts to molecular testing of the first portion of urine or a swab. [5]

Table 1. What types of glass tests exist today?

Option	Where is it used?	The main goal
2-glass pre-massage and post-massage test	Men with suspected chronic bacterial prostatitis	Compare urine before and after prostate massage
Mears-Stamey 4-cup test	Men with suspected chronic bacterial prostatitis	Localize the source of bacteria and leukocytes between the urethra, bladder and prostate
3-glass test for hematuria	Adults with visible blood in urine	To roughly understand at what stage of urination blood appears

The table is compiled based on modern urological recommendations and reviews on prostatitis and hematuria. [6]

When a glass sample is really needed, and when its role is already limited

The most substantiated modern indication for the glass test is suspected chronic bacterial prostatitis in a man with recurrent urinary tract infections, chronic dysuria, pelvic pain, or persistent lower urinary tract symptoms, when localization of the bacterial process specifically to the prostate is desired. In 2025, the European Association of Urology explicitly recommended performing the 2- or 4-glass test in patients with chronic bacterial prostatitis. This is one of the few conditions where the method still has a formal place in guidelines. [7]

However, in the same group of chronic pelvic pain patients, the importance of testing should not be overestimated. The European Association of Urology's guidelines for chronic pelvic pain state that such tests are of limited benefit in primary prostatic pain syndrome, and positive localizing cultures occur in approximately 8% of patients with suspected prostatic pain syndrome, which is comparable to the proportion of asymptomatic men with similar findings. This means that pain and dysuria without confirmed bacterial localization should not automatically translate into a diagnosis of bacterial prostatitis. [8]

The second situation where the test is still considered is visible hematuria. Historically, the three-glass scheme was used to divide hematuria into initial, terminal, and total. This approach can still be useful as part of the history and initial evaluation. Initial and terminal hematuria more often indicate a source in the lower urinary tract, while total hematuria is more concerning for a bladder or upper urinary tract source. However, modern urology does not consider this sufficient for a definitive examination. [9]

For microhematuria, a cup sample is no longer the standard decision-making test. American Urological Association guidelines base management on microscopic confirmation of microhematuria and risk stratification based on the likelihood of urologic malignancy. This means that cup urine collection for asymptomatic microhematuria does not replace the standard algorithm. [10]

There are also situations where the glass test has given way to more accurate methods. When urethritis is suspected, especially when associated with sexually transmitted infections, the first portion of urine and molecular tests for chlamydia and gonococcal infections are now more important. The US Centers for Disease Control and Prevention (CDC) recommends that for urethritis in men, the focus should be on discharge, leukocyte esterase, microscopy of the first portion of urine, and molecular tests, rather than the classic multi-cup protocol. [11]

Table 2. When the glass test is useful and when it is not

Clinical situation	The role of the glass sample today
Suspected chronic bacterial prostatitis	Useful and formally recommended
Primary prostatic pain syndrome without proven infection	Limited diagnostic value
Visible hematuria	A helpful guide, but not a definitive test
Microhematuria	It is not a modern core algorithm.
Acute bacterial prostatitis	Not applicable, massage is contraindicated
Suspected chlamydial or gonococcal urethritis	First urine sample and molecular tests are usually preferred.

The table is compiled according to the recommendations of the European Association of Urology, the American Urological Association and the US Centers for Disease Control and Prevention. [12]

How to perform the 2-, 3-, and 4-glass tests correctly

Proper execution of the cup test is critical because the method is highly sensitive to errors during the collection phase. If portions are mixed up, the patient interrupts the flow, samples sit for a long time before being delivered to the lab, or prostate massage is performed incorrectly, the interpretation is significantly less valuable. This is why the cup test is one of those studies where the preanalytical stage is almost as important as the laboratory portion itself. [13]

The Mears-Stamey 4-glass test is the most detailed and time-consuming procedure. First, the first portion of urine, which primarily represents the urethra, is collected. Then, the midstream urine, more representative of the bladder, is collected. After this, the physician gently massages the prostate and either obtains prostatic secretions or immediately collects post-massage urine, which serves as a washout of prostatic secretions from the urethra. Microscopy, leukocyte count, and bacterial culture are possible for all portions. [14]

The 2-glass pre- and post-massage test is simpler. First, a midstream urine sample is obtained before prostate massage. Then, after gentle massage, the first portion of urine, which already contains components of prostatic secretions, is collected. A 2006 study demonstrated good agreement between this method and the classic 4-glass test, and the 2025 European guidelines recognize it as an acceptable alternative in clinical practice. This is why it is used more often in practical urology than the full 4-glass technique. [15]

The three-glass test for hematuria is performed differently. There is no prostate massage. Without interrupting urination, the patient sequentially collects the beginning, middle, and end of the urine stream in three separate containers. According to classical logic, blood in only the first portion is considered initial hematuria, blood in only the last portion is considered terminal, and blood in all portions is considered total hematuria. However, even with ideal collection, this result remains approximate, not definitive. [16]

It's crucial to remember the contraindications. Prostate massage should not be performed in cases of acute bacterial prostatitis. European guidelines state this as a strong recommendation. In this situation, a midstream urine sample, urine culture, and, if systemic symptoms are present, a blood culture are required. Therefore, the 2-glass and 4-glass tests are methods for chronic localizing testing, not for acute febrile prostatitis. [17]

Table 3. How to collect different types of glass samples

Option	What do they collect?	Key feature
2-glass test for prostatitis	The middle portion before the massage and the first portion after the massage	Prostate massage is required between samples.
Mears-Stamey 4-cup test	First portion, middle portion, prostate secretion, post-massage urine	The most detailed, but most labor-intensive scheme
3-glass test for hematuria	Initial, middle and final portions of 1 urination	No massage, just sequential collection

The table is based on a study comparing the 2- and 4-glass test and on European urological recommendations. [18]

Table 4. Common mistakes when collecting material

Error	What is dangerous?
The portions are mixed up	The localizing meaning of the test is lost
Urination is interrupted	The distribution of cells and blood is distorted
Long delay before sowing	The reliability of bacteriological assessment is reduced
Prostate massage was performed for acute prostatitis.	Risk of deterioration and bacteremia
The wrong sample was collected for a molecular test for sexually transmitted infections.	It is possible to miss a urethral infection
Interpretation without clinical context	False conclusions about the localization of the process

The table is based on current urological and infectious disease guidelines.[19]

How to interpret the 2- and 4-glass tests when chronic prostatitis is suspected

The rationale behind the 2- and 4-glass tests for prostatitis is based on a comparison of the samples. If bacteria and leukocytes appear or significantly increase in prostatic secretions and post-massage urine, while they are less pronounced in earlier samples, this supports localization of the process within the prostate. The 2025 European guidelines explicitly identify the 4-glass test as the optimal test for diagnosing chronic bacterial prostatitis, and the 2-glass test as a similarly sensitive alternative. [20]

The classic approach considers a 10-fold increase in bacterial growth in prostatic fluid or post-massage urine compared to early urine samples to be the most convincing. This interpretation has historically been entrenched in urology and is still used as a guideline in the literature and practice reviews on chronic bacterial prostatitis. However, the results should not be interpreted mechanically. What is important are symptoms, recurrent infections, the repeatability of the finding, and the absence of a simpler explanation, such as contamination or a current bladder infection. [21]

However, leukocyturia after massage alone does not indicate bacterial prostatitis. It may indicate inflammation, but not necessarily an active bacterial infection. Therefore, culture and localization of the uropathogen are more important than an isolated increase in leukocyte count. This is especially important in patients with chronic pelvic pain, in whom inflammatory and non-infectious mechanisms often coexist. [22]

The limitations of the method must also be considered. A 2006 study showed that the 2-glass test correctly predicted diagnosis in over 96% of those examined, but the authors simultaneously emphasized that the clinical value of leukocyte and uropathogen localization remains controversial, especially in severely and repeatedly treated patients. This means that a positive test can be useful at the first presentation, but does not always equally well explain protracted and complex cases. [23]

The current practical purpose of a localization test for chronic bacterial prostatitis is to confirm that the infectious reservoir is truly located in the prostate, and not just in the urethra or bladder, and thus justify longer, culture-directed antibacterial therapy. However, it should not become a routine test for every man with pelvic pain. If the clinical picture is more consistent with primary pain syndrome, the results of a localization test may add little value. [24]

Table 5. How results are usually read in chronic bacterial prostatitis

Pattern	What is more likely?
Bacteria and leukocytes mainly in the early portion	Most likely a urethral source
The middle portion is positive without prostatic enhancement	Most likely a bladder or general urinary tract infection
A sharp increase in prostate secretion and post-massage urine	Supports localization in the prostate
Approximately 10-fold increase in bacteria in prostate samples compared to early portions	Classic criteria for chronic bacterial prostatitis
There are leukocytes, but there is no convincing bacterial enhancement.	A non-bacterial inflammatory process or pain syndrome is possible

The table is compiled according to European urological guidelines and modern reviews on chronic bacterial prostatitis. [25]

How to interpret a 3-glass test for hematuria

The historical value of the 3-glass test for hematuria is based on the time it takes for blood to appear during urination. If blood is visible at the beginning of the stream and then disappears, this is called initial hematuria. If the urine is initially clear and blood appears toward the end of urination, this is called terminal hematuria. If blood is present throughout the entire urination, this is called total hematuria. This pattern remains clinically understandable and useful for patient communication. [26]

Initial hematuria traditionally suggests a urethral source of bleeding. Terminal hematuria is more often associated with the bladder neck, prostatic urethra, or lower urinary tract. Total hematuria raises concerns about the bladder and upper urinary tract. However, all of these formulas are probabilistic, not absolute. They are helpful for orientation, but do not replace endoscopy and visualization. [27]

The current role of the 3-glass test for visible hematuria has become more modest. A 2018 study published in the journal Nature found that men with initial and terminal visible hematuria were more likely to have lower urinary tract pathology, while no significant upper urinary tract tumors were found. However, even this study emphasized that flexible cystoscopy remained mandatory. This reflects the current clinical position: the 3-glass test can provide guidance, but does not replace a full examination. [28]

For microhematuria, this logic is even weaker. Here, blood is not visible to the naked eye, meaning that cup-by-cup testing typically does not provide the same practical information as confirmed microscopy, repeat testing, and risk-based urological assessment. This is why current American guidelines focus on risk stratification rather than the three-cup test. [29]

The practical conclusion is this: the 3-glass test for hematuria is a useful historical and clinical tool and a way to better characterize the symptoms, but it is not a standalone modern diagnostic strategy. For visible hematuria, the mainstay of the diagnostic approach remains examination, urinalysis, cystoscopy, and upper urinary tract imaging. For microhematuria, confirmation by microscopy and risk-stratified testing are required. [30]

Table 6. Classic interpretation of the 3-glass test for hematuria

Blood distribution	Classical indicative interpretation
Blood only in the first portion	Initial hematuria, most likely urethra
Blood only in the last portion	Terminal hematuria, most likely the bladder neck, prostatic urethra
Blood in all 3 portions	Total hematuria, most likely bladder or upper urinary tract
The history is unclear or the blood appears unpredictably	It is impossible to draw a reliable conclusion based on a sample alone.

The table is based on current reviews of visible hematuria and clinical practice in urologic examination.[31]

What is the glass test supplemented or replaced with today?

In modern urology, the cup test is almost never used in isolation. If chronic bacterial prostatitis is suspected, it is supplemented by a general urinalysis, urine culture, sometimes tests for atypical pathogens, and, if indicated, a transrectal ultrasound to rule out an abscess. The 2025 European guidelines specifically emphasize that patients with chronic bacterial prostatitis should undergo microbiological evaluation for atypical pathogens such as chlamydia and mycoplasma. [32]

If an acute bacterial prostate infection is suspected, the route is different. A midstream urine sample, urine culture, blood culture if systemic symptoms are present, and a gentle rectal examination without massage are required. Prostate massage not only provides no useful information but can also be dangerous. Therefore, the same prostate complaint in a chronic and acute situation leads to fundamentally different diagnostic strategies. [33]

When urethritis is suspected, the primary focus has shifted to the first urine sample and molecular testing. The US Centers for Disease Control and Prevention recommends that men with signs of urethritis have their first urine sample tested for leukocyte esterase or sediment microscopy, as well as molecular testing for chlamydial and gonococcal infections. This provides a much more accurate answer to the clinical question than attempting to localize the inflammation using several glasses. [34]

In the case of hematuria, current diagnostic methods include cystoscopy and upper urinary tract imaging. The 2025 update of the American Urological Association guidelines emphasizes a risk-based approach to microscopic hematuria, while for visible hematuria, major urology sources maintain consensus on the need for bladder and upper urinary tract evaluation. Therefore, a 3-glass test today often supplements the history rather than directs the entire examination. [35]

This is why the actual role of the glass test in 2026 appears to be as follows: it's not extinct, but it's also not a universal test. It's primarily useful in localizing chronic bacterial prostatitis and in the descriptive assessment of visible hematuria. In all other scenarios, physicians increasingly rely on more targeted methods—molecular tests, cultures, cystoscopy, ultrasound, CT scanning, and risk-stratified algorithms. [36]

Table 7. What is often more important today than the glass sample itself

Clinical task	More significant modern methods
Chronic bacterial prostatitis	2- or 4-glass test plus culture and clinical evaluation
Acute bacterial prostatitis	Midstream urine, urine culture, blood culture, evaluation for systemic infection
Urethritis	First urine sample and molecular testing for sexually transmitted infections
Visible hematuria	Cystoscopy and upper urinary tract imaging
Microhematuria	Confirmatory microscopy and risk-stratified route
Recurrent urinary tract infections in men	Urine culture, prostatic reservoir search, visualization as indicated

The table is compiled according to European urological guidelines, recommendations of the American Urological Association and the US Centers for Disease Control and Prevention. [37]

Frequently Asked Questions

Are a cup test and a standard urine analysis the same thing?
No. A standard urine analysis evaluates a single sample, while a cup test compares multiple urine samples to roughly locate the source of cells, bacteria, or blood. These are different tests.

Is the 2-glass test suitable for women?
In modern clinical usage, the 2-glass pre- and post-massage test pertains to the diagnosis of chronic bacterial prostatitis, i.e., male urology. For women, the term "2-glass test" is sometimes commonly understood to mean dividing the urine stream into two portions, but this is not the localizing prostatic test described in urological manuals. [39]

Is it possible to perform a glass test for acute prostatitis with fever?
No, not if we're talking about the option involving prostate massage. European guidelines explicitly prohibit prostate massage in acute bacterial prostatitis. In this situation, a midstream urine sample, urine culture, and, if systemic manifestations are present, blood culture are required. [40]

Has the 2-glass test completely replaced the 4-glass test?
No. The 4-glass test is still considered the optimal test for diagnosing chronic bacterial prostatitis, but the 2-glass test is recognized as having similar diagnostic sensitivity and is much more convenient for practical use. Therefore, it is more commonly used in clinical settings. [41]

Can a 3-glass test replace cystoscopy for blood in the urine?
No. It can indicate at what stage of urination the blood appears, but modern examination for visible hematuria still relies on cystoscopy and visualization of the upper urinary tract. [42]

If there's blood only in the first portion, does that mean the problem is definitely in the urethra?
Not necessarily. This is a classic, indicative interpretation, but it's not absolute. Even with typical initial or terminal hematuria, a full urological examination may still be necessary. [43]

What's more important when suspecting a sexually transmitted infection: a glass sample or the first urine sample?
Today, the first urine sample is more important for molecular testing. In urethritis, it is used to detect chlamydial and gonococcal infections and better addresses the current diagnostic question. [44]

Can a glass test accurately differentiate bacterial prostatitis from pain syndrome without infection?
Not always. A positive localizing bacterial finding supports chronic bacterial prostatitis, but in patients with chronic pelvic pain without a convincing bacterial localization, the test is of limited help. Therefore, the result is always evaluated in conjunction with symptoms, cultures, and the overall clinical context. [45]