Prostate Specific Antigen (PSA)

Prostate specific antigen (PSA) is a type of protein produced by cells in the prostate. The prostate is a small reproductive gland that helps make semen, the fluid that transports sperm from the testicles through the penis during ejaculation. Healthy prostates create low levels of PSA. An elevated level of PSA may indicate a problem with the prostate.

The PSA test uses a blood sample to measure a person’s PSA level. In some patients, the PSA test may be used for prostate cancer screening. The PSA test is also used to help with the diagnostic process for prostate cancer and noncancerous prostate conditions, as well as to monitor people who have been diagnosed with these conditions.

Purpose of the test

A PSA test can determine if you have high levels of PSA in your blood. Normally, PSA is produced and released within the prostate gland, where it helps make semen and plays an important role in fertility. Only small amounts of PSA move out of the prostate and into the blood in healthy people, but several prostate conditions can cause higher levels of PSA in the blood.

A doctor may order a PSA test for several reasons:

Cancer screening: Cancer screening checks for cancer in people who don’t have symptoms. People with prostate cancer often have elevated levels of PSA in their blood, but elevated levels are also found in people without prostate cancer. The decision about whether or not to use a PSA test to screen for prostate cancer is highly individualized based on a patient’s risk factors and health history. Patients should work with their doctor to understand the risks and benefits of PSA screening for their specific situation.

Diagnosis: If you have symptoms of a prostate condition, or if your prostate gland is not normal during a physical exam, your doctor may recommend a PSA test. An elevated level of PSA may indicate an issue in the prostate such as prostate cancer, benign prostatic hyperplasia (BPH), or inflammation of the prostate. This then may lead to more follow-up testing to determine the diagnosis.

Monitoring and follow-up: If you’ve been diagnosed with prostate cancer or BPH, your doctor may order PSA tests to monitor the effects of treatment. For those who have completed treatment for prostate cancer, the PSA test can be used to check for signs that the cancer has come back.

What does the test measure?

The PSA test measures levels of prostate specific antigen in the blood. The results indicate the amount of PSA in a certain volume of blood. Results are usually expressed as nanograms of PSA per milliliter (ng/mL) of blood.

How to get tested

Samples used for PSA testing are collected by trained health care professionals at hospitals, labs, and other medical settings. Before getting tested, it’s best to talk to your doctor about the risks and benefits of PSA testing. You may be able to schedule your own PSA test at a clinic or laboratory without a doctor’s order. However, you will need a doctor to interpret the results of your test and recommend next steps.

Can I take the test at home?

Although testing for PSA at home is uncommon, several at-home PSA tests are available. At-home PSA tests typically involve collecting samples of blood at home through a fingerstick and sending the samples into a laboratory for testing. When considering at-home PSA testing, it’s important to understand the potential harms of this test.

At-home testing may be less accurate than testing a sample taken from a vein. PSA testing can also show a higher result when cancer isn’t present and can lead to additional diagnostic procedures. Because the role of PSA testing is highly individualized, it’s important to seek testing only under the care and guidance of a doctor.

How much does the test cost?

The price of a PSA test will vary based on where the test is conducted and whether you have health insurance. If you have health care coverage, you can reach out to your insurance provider directly to find out what a PSA test will cost under your plan. Depending on your plan, you may be responsible for out-of-pocket costs, such as copays and deductibles.

The cost of at-home PSA testing ranges from about $30 to $70.

During a blood draw, a healthcare professional will use a small needle to take a sample of blood from a vein in your arm before sending the sample to a laboratory for analysis.

A rapid PSA test has also been approved for use by the FDA. Rapid PSA tests allow doctors to measure PSA in their office using a finger prick to obtain a few drops of blood without sending samples to a laboratory.

Before the test

There are several precautions patients should consider before a PSA test. Because certain drugs can cause PSA levels to increase, it’s important to talk to your doctor about any medications you’re taking. You should also tell your doctor about any recent procedures or situations that affect your urinary system, including injuries, surgeries, and infections.

Patients may be advised to avoid having sex or masturbating for 24 hours before your blood draw. Your PSA level can rise after releasing semen, so a day of abstinence can ensure you get the most accurate results.

During the test

Having your blood drawn often begins with a healthcare provider locating an appropriate vein, usually in your arm, and tying an elastic band above the site to increase blood flow. The area is cleaned to remove germs on the skin before a needle is inserted into the vein. Blood is then drawn out of the arm into a sample tube used for collection. Blood draws typically take less than five minutes.

Providing a blood sample for a PSA test should be a quick and relatively painless process. You may feel a brief sting from the needle prick, and you might experience minor bruising around the spot the needle is inserted. Any discomfort should go away quickly.

A finger prick test is conducted by pricking your fingertip with a device that contains a small needle in order to obtain a few drops of blood.

After the test

After your blood is drawn, the elastic band is removed and the site of the blood draw is bandaged. There are no special precautions or restrictions recommended after receiving a PSA blood test. After you are tested, you are able to drive and go about your daily activities as usual.

Receiving test results

After your blood sample is taken, it is sent to a laboratory for analysis, so it may take several days to receive your results. Rapid PSA testing provides results in less than 15 minutes while you wait in the doctor’s office.

Interpreting test results

PSA test results should be interpreted with caution and under the guidance of a doctor. In understanding your test results, your doctor will consider a variety of factors, including your age, ethnicity, and medications you are taking. Additionally, doctors rarely make clinical decisions based on a single elevated PSA test result. Rather, doctors may look for trends in a patient’s PSA level over time and look at other diagnostic results as well.

Cancer screening: If you receive a high PSA result from a screening, your doctor may recommend follow up tests to help diagnose the cause. Additional tests may include a urine test to check for a urinary tract infection and/or a physical exam of the prostate, called a digital rectal exam. Repeat PSA testing may be recommended to look for trends.

Diagnosis: A high PSA result may also prompt a doctor to recommend a biopsy if they suspect cancer. However, most people who are referred for a biopsy based on a high PSA level do not have cancer. Elevated PSA levels are more often a sign of non-cancerous conditions such as a urinary tract infection, prostatitis, or benign prostatic hyperplasia (BPH). These conditions are unrelated to prostate cancer.

Monitoring and follow-up: If you receive an elevated PSA test result during or after prostate cancer treatment, it is important to talk to your doctor about what test results mean for you. If you are currently undergoing treatment for prostate cancer, consistently elevated levels of PSA may indicate a need to reevaluate the treatment. If you have a rising PSA level after completing cancer treatment, your doctor will consider the type of treatment you received when interpreting PSA test results. In some patients, a rising PSA after completing treatment for prostate cancer indicates that the cancer has returned.