Prostate-specific antigen (PSA) is a type of protein made by normal prostate cells and also by cancer cells. It’s found in a man’s blood and semen. Doctors measure the amount found in your blood to find out your risk of having prostate cancer.

When you’re being treated for prostate cancer, one way to see if the treatment is working is to keep track of PSA levels. Rising PSA levels could mean your cancer has returned.

But one high PSA test result isn’t cause for panic. Tracking PSA levels isn’t an exact science. There are many factors that go into why a man’s numbers could be high, aside from having cancer.

Your doctor won’t make treatment decisions based on PSA measurement alone. They’ll need additional tests to confirm the cancer has returned. If your numbers come back high, don’t be afraid to ask your doctor questions. Discussing all possible options is a good way for you both to work together to rule out other causes.

Here are some questions you can ask about your PSA results to help you get a better understanding of what they mean.

Is there another condition that could be causing my levels to be higher?

Prostate cancer isn’t the only medical condition that can raise your PSA levels.

Others include:

  • Enlarged prostate: As you get older, your prostate can become enlarged. But this doesn’t necessarily mean you have cancer.
  • Inflammation: A prostate gland can get an infection, which causes inflammation and can also make PSA go up.
  • Urinary tract infection: A urine test can be done to rule out any infection that can interfere with PSA numbers.

Is it possible my test is giving a false positive?

One measurement of high PSA levels after cancer treatment doesn’t guarantee the cancer has returned. It’s possible for the test to give a false-positive result. In order to avoid confusion, your doctor may have you do a second test or compare the numbers from your other tests leading up to this one.

There are also specialty tests to measure PSA that can help your doctor get more information.

The free PSA (fPSA) test measures what percentage of the total PSA is floating in your bloodstream. If you have a lower fPSA to total PSA ratio, you have a higher risk of having prostate cancer.

Complexed PSA measures only the PSA attached to other proteins in your blood.

Could I have done something before being tested to raise my levels?

Sometimes outside factors can cause your PSA levels to be higher at the time of the test. These include:

  • ejaculating a day or two before the test
  • taking a multivitamin or other supplement
  • taking certain medications
  • having a prostate exam before the PSA test

If you can check off anything from this list, ask your doctor whether that could be contributing to your results.

Have my levels been going up over time, or is this the first test that’s shown cause for concern?

During your treatment for prostate cancer, your doctor will probably test your PSA levels regularly. Part of determining whether or not the cancer has returned or spread is monitoring how fast your levels have gone up. This is called measuring the velocity. Ask your doctor how this PSA test compares to your last few.

Some slow increase as you get older is normal, but a faster increase over a short period isn’t.

I don’t have any other symptoms. Does this mean I should still be worried?

Symptoms of prostate cancer can include problems urinating and difficulty getting an erection and ejaculating. But it’s also possible to have cancer without noticing any symptoms.

Whether you’re experiencing any type of symptoms or none at all, it’s worth bringing up to your doctor. These details can help them figure out future tests and treatments. Symptoms of prostate cancer can also be symptoms of other problems, like enlargement or infection.

Do you recommend a biopsy? Why?

Many times doctors can’t get a clear picture based on PSA numbers alone, so they may want to do a biopsy. In this procedure, your doctor takes a sample of prostate tissue to check for cancer cells. This is the most accurate way to find out if the cancer has returned.

If your doctor is recommending a biopsy based on these numbers, there is nothing wrong with asking for extra information. Tell the doctor you’d like them to explain why a biopsy is the best option for your situation.