What Is a PSA Test and What Does It Tell You About Your Prostate?
Learn what a PSA test measures, what high PSA levels can mean, and when men may want to discuss prostate cancer screening with a doctor.
A PSA test is a simple blood test that measures a protein made by cells in the prostate. Many men first hear about PSA testing when they reach middle age, but understanding what the test actually tells you can make the subject much less confusing.
A PSA result can provide useful information about prostate health, but it does not by itself diagnose prostate cancer. Several prostate conditions can affect PSA levels, and the decision to have the test depends on factors such as age, family history, risk factors, and personal preferences.
What Does PSA Stand For?
PSA stands for prostate-specific antigen.
It is a protein produced by normal prostate cells as well as prostate cancer cells. A small amount of PSA normally enters the bloodstream, where it can be measured with a blood test.
The test is commonly associated with prostate cancer screening, but doctors can also use PSA testing when evaluating prostate symptoms or monitoring someone who has already been diagnosed with prostate cancer.
This is important because a PSA test is not simply a test that tells you whether you have cancer.
What Can Cause a High PSA Level?
A higher-than-expected PSA result can happen for several reasons.
An enlarged prostate
Benign prostatic hyperplasia, commonly called BPH, is a noncancerous enlargement of the prostate that becomes more common as men get older.
BPH can cause urinary symptoms such as a weak urine stream, difficulty starting urination, frequent trips to the bathroom, and difficulty completely emptying the bladder. It can also raise PSA levels.
This means that an elevated PSA does not automatically mean that prostate cancer is present.
Prostatitis
Prostatitis is inflammation of the prostate. Depending on the type, it can cause pelvic discomfort, problems with urination, pain, and sometimes fever or chills.
Inflammation of the prostate can also cause PSA levels to rise.
Prostate cancer
Prostate cancer can increase PSA levels because cancerous prostate cells can produce PSA.
However, PSA testing cannot determine on its own whether an elevated result is caused by cancer, an enlarged prostate, inflammation, or another factor. Further evaluation may be needed when a result is concerning.
Does a High PSA Mean You Have Cancer?
No.
This is one of the most important things to understand about PSA testing.
There is no single PSA number that can definitively separate men with prostate cancer from men without it. PSA levels tend to increase as men get older, and conditions such as BPH and prostatitis can also increase the level.
Doctors therefore look at the result in context rather than treating one number as a diagnosis.
Depending on the situation, they may consider your age, symptoms, medical history, family history, previous PSA results, medications, and other test results.
An abnormal PSA may lead to additional testing or closer monitoring. It does not automatically mean that a biopsy or cancer treatment will be necessary.
What Is Considered a Normal PSA Level?
There is no single PSA number that can be described as normal for every man.
You may hear 4.0 ng/mL mentioned as a traditional cutoff, but PSA interpretation is more complicated than simply saying that anything below 4.0 is safe and anything above it is dangerous.
PSA levels can vary with age, and some medications used to treat BPH, including finasteride and dutasteride, can lower PSA levels. Doctors need to know about these medications when interpreting a result.
This is why it is better not to interpret a PSA result without considering the circumstances surrounding the test.
When Should Men Consider a PSA Test?
There is no universal answer that applies to every man.
In the United States, the U.S. Preventive Services Task Force recommends that men between 55 and 69 make an individual decision about PSA-based screening after discussing the potential benefits and harms with a clinician. For men aged 70 and older, the USPSTF recommends against routine PSA-based screening.
Other organizations use somewhat different age recommendations.
The American Cancer Society recommends that men discuss prostate cancer screening with a healthcare provider starting at age 50 for those at average risk who are expected to live at least another 10 years. The conversation should begin at age 45 for men at higher risk, including Black men and men with a father or brother diagnosed with prostate cancer before age 65. Men with more than one first-degree relative diagnosed at an early age are advised to discuss screening starting at age 40.
These differences are one reason prostate cancer screening is best approached as a conversation rather than a one-size-fits-all schedule.
What Makes Someone More Likely to Need Earlier Screening?
Age is an important risk factor for prostate cancer, but it is not the only one.
Family history can increase risk. A man whose father or brother had prostate cancer may have a higher risk than someone without that history.
Race and ethnicity can also affect risk. The American Cancer Society identifies Black men as having a higher risk of prostate cancer and recommends discussing screening earlier for this group. Certain inherited genetic changes, including BRCA-related variants, can also increase risk.
If you have one or more of these risk factors, it is worth discussing them with your healthcare provider rather than relying only on your age to decide when testing makes sense.
What Happens If Your PSA Is Elevated?
An elevated result does not automatically mean that something serious is happening.
Your healthcare provider may look at your previous PSA results, ask about symptoms, review medications, and consider other possible causes of the elevated level.
Depending on the situation, additional testing or follow-up may be recommended.
One reason doctors are careful about PSA screening is that testing can sometimes produce a false-positive result. This can lead to additional procedures, including prostate biopsy, even when cancer is not ultimately found.
There is also a possibility of finding a prostate cancer that would never have caused serious problems during a man's lifetime. This is known as overdiagnosis and is one of the reasons screening decisions involve weighing potential benefits against potential harms.
Should You Get a PSA Test If You Have Urinary Symptoms?
Urinary symptoms should not be automatically blamed on the prostate.
A weak urine stream, frequent urination, difficulty starting, dribbling, or trouble emptying the bladder can occur with prostate problems, but other urinary conditions can cause similar symptoms.
A PSA test may be part of an evaluation, but it is only one piece of information.
If you notice a persistent change in urination, blood in your urine, pelvic pain, or difficulty emptying your bladder, speaking with a healthcare professional is more useful than trying to determine the cause from a PSA number alone. NIDDK advises men with urinary problems to seek professional evaluation, particularly when they cannot pass urine, have blood in the urine, or have painful urination.
The PSA Test Is Information, Not a Diagnosis
The PSA test can be a useful tool for understanding prostate health, but it is not a simple pass-or-fail test.
A higher PSA can occur with prostate cancer, but it can also occur with an enlarged prostate or inflammation. A lower result does not eliminate every possibility of prostate disease either.
The most useful way to think about PSA testing is as one piece of a larger health picture.
If you are approaching the age when prostate cancer screening becomes relevant, or if you have a family history or other risk factors, talk with your healthcare provider about whether testing makes sense for you. The right decision depends on your individual risk, health history, and how you weigh the possible benefits and downsides of screening.
Sources
National Cancer Institute, Prostate-Specific Antigen (PSA) Test
https://www.cancer.gov/types/prostate/psa-fact-sheet
U.S. Preventive Services Task Force, Final Recommendation Statement: Screening for Prostate Cancer
https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/prostate-cancer-screening
American Cancer Society, American Cancer Society Recommendations for Prostate Cancer Early Detection
National Institute of Diabetes and Digestive and Kidney Diseases, Prostate Problems
https://www.niddk.nih.gov/health-information/urologic-diseases/prostate-problems
National Institute of Diabetes and Digestive and Kidney Diseases, Symptoms & Causes of Bladder Control Problems