The prostate-specific antigen test is a blood test that measures levels of a protein the prostate gland produces. Men with prostate cancer usually have elevated levels of this protein, but heightened levels do not always mean cancer.
Other health conditions may also cause prostate-specific antigen (PSA) levels to rise. In some cases, an elevated PSA is temporary and not a sign of a health problem at all.
Cells in the prostate gland produce PSA and levels typically remain below 4 nanograms per milliliter (ng/mL).
Most men with prostate cancer have PSA levels above 4 ng/mL, but about 15 percent of men with a PSA level below 4 ng/mL are also diagnosed with prostate cancer. This means that a PSA test alone cannot rule out or diagnose prostate cancer but can identify whether a man is at higher risk of having or developing the disease.
Initial testing may include both a PSA test and a digital rectal exam (DRE). During this examination, a doctor inserts a finger into the rectum to check the prostate for abnormalities. Together, if these two tests suggest prostate cancer, then the doctor will arrange for a biopsy to confirm the diagnosis.
False positives - a high PSA level, but no cancer - on the PSA test are common. PSA levels rise with age and other factors. Men with high PSA levels should follow up with a doctor, but should not assume they have cancer.
Health conditions, lifestyle factors, and testing inconsistencies can all lead to high PSA test results. A doctor can explain which factors are most relevant to each person, and whether delaying testing or planning additional tests might help determine the cause of the high PSA test results.
Besides prostate cancer, other factors may cause elevated PSA levels. These include:
A person's PSA levels tend to increase slowly with age. Men over 50 years should talk to their doctor about their risk of developing prostate cancer and the benefits and risks of PSA screening.
Not all sources agree on whether to routinely test PSA levels in men over 70, as some data suggest that it does not improve cancer survival rates and may result in over-diagnosis and over-treatment.
Therefore, it is important that individuals discuss screening options with a doctor based on their family and personal medical history.
Prostatitis is inflammation of the prostate, sometimes due to a bacterial infection. Men with prostatitis may have elevated PSA numbers.
Prostatitis can also be a chronic problem. Men with prostatitis may have trouble urinating, experience pain when urinating, develop a fever, feel pressure in the rectum, have difficulties ejaculating, and notice changes in sexual function.
3. Benign prostatic hyperplasia
Benign prostatic hyperplasia (BPH) is an enlarged prostate that can raise PSA levels. BPH is a common condition in older men.
BPH does not increase the risk of prostate cancer, but the symptoms can be similar to prostate cancer. Men with BPH often experience irritation while urinating.
4. Medical procedures
Medical procedures on the prostate can elevate PSA levels. A recent prostate exam, having a urinary catheter, or inserting a scope into the urethra can cause false positives on the PSA test.
For the most accurate results, a person should wait a few weeks following a medical procedure before undergoing the PSA test.
5. Urinary tract infection
A urinary tract infection (UTI) is an infection of the urethra or bladder that can cause PSA levels to rise. Men with a UTI may experience pain during urination, blood in the urine, or an inability to urinate. In most cases, a simple urine test can accurately diagnose a UTI.
6. Vigorous exercise
Running and doing other forms of vigorous exercise a day or two before a PSA test may result in a false positive. A person should ask their doctor about exercise recommendations before scheduling a PSA test.
Ejaculating during the 48-hour period before a PSA test can cause PSA levels to rise temporarily. Men planning a PSA test should avoid masturbating or sexual activity for 2-3 days before the test.
Men who have scheduled a PSA test should tell their doctors about any prostate symptoms they experience. Changes in ejaculation or urination often point to a problem with the prostate.
Rectal pain, abdominal pressure, fever, and signs of an infection may also indicate a prostate issue.
The symptoms of prostate cancer include:
- painful ejaculation
- blood in semen or urine
- hip, pelvis, low back, or thigh pain
- a weak urine flow
- problems urinating
- incontinence or increased urges to urinate
- difficulty getting or maintaining an erection
- burning during urination
These symptoms are the same as or similar to many other prostate issues, including prostatitis and BPH. Men who have symptoms of a prostate problem will usually require additional testing, such as urine screenings for a UTI or a digital rectal exam to test for prostate abnormalities. Prostate cancer may cause no symptoms in the early stages.
High PSA levels can be a source of immense anxiety, particularly in men who have to wait several weeks for a follow-up appointment with their doctors. This is why most guidelines recommend that men and their doctors carefully consider the risks and benefits of PSA screening.
Research increasingly suggests that the development of prostate cancer may be normal in older men. While regular preventative health checks can be beneficial, some men may choose to avoid the PSA test, depending on their age and other risk factors.
Men should know that detecting prostate cancer early does not
When a man has a high PSA but no lumps in the prostate, a doctor might redo the test, recommend continuing to monitor PSA levels, or recheck the prostate in a few months. Men should discuss the benefits and drawbacks of each strategy with a doctor.
The PSA is a sensitive test that can commonly produce false positives. While this helps it to detect most cases of cancer, this also means the test can cause much anxiety in men who do not have cancer.