The main screening tests: PSA blood test and digital rectal exam

Doctors use two main tests to look for prostate cancer: a blood test that measures prostate-specific antigen (PSA), and a physical exam called a digital rectal exam (DRE). The PSA test measures a protein the prostate makes—higher levels can signal cancer, but they can also mean infection, enlargement, or age-related changes. The DRE involves a doctor inserting a gloved finger into the rectum to feel the prostate's size, shape, and texture.

Neither test is perfect. A high PSA result does not mean you have cancer, and some men with cancer have normal PSA levels. The DRE can miss cancers the doctor cannot feel. Because of this uncertainty, major medical organizations—including the American Cancer Society and the U.S. Preventive Services Task Force—recommend that men discuss the pros and cons of screening with their doctor before testing begins, rather than screening everyone automatically.

Key Takeaways

  • The PSA blood test and digital rectal exam are the two screening tests doctors use, but neither is definitive on its own.
  • A high PSA level can come from cancer, infection, enlargement, or simply age, so doctors usually repeat the test or order imaging before assuming cancer.
  • If screening results are concerning, a biopsy—removing tiny tissue samples from the prostate—is the only way to confirm cancer.
  • Men should discuss screening with their doctor before testing, because the benefits and harms of early detection vary by age and health.

What happens after a high PSA or abnormal DRE result

If your PSA is elevated or your doctor feels something unusual during the DRE, the next step is usually not a biopsy right away. Your doctor may repeat the PSA test weeks or months later to see if the level stays high or drops. They may also order an ultrasound or an MRI to get a picture of the prostate and look for suspicious areas.

The PSA velocity—how fast your PSA is rising over time—matters more than a single high number. A PSA that jumps from 2 to 8 in one year is more concerning than a PSA that has been stable at 5 for five years. Your doctor will also consider your age, family history, and race, because prostate cancer risk varies by these factors.

Prostate biopsy: how it works and what to expect

A prostate biopsy is the only test that can confirm cancer. A doctor uses ultrasound to guide a thin needle into the prostate and removes 10 to 12 small tissue samples from different areas. The procedure takes 10 to 15 minutes and is usually done in an office or outpatient clinic with local anesthetic.

You may feel pressure or a brief sharp sensation as each sample is taken. Afterward, you might see blood in your urine, stool, or semen for a few days—this is normal. Serious complications like infection or heavy bleeding are uncommon but possible. Your doctor will give you antibiotics before the biopsy to reduce infection risk. Results come back in about a week, showing whether cancer is present and, if it is, how aggressive it appears.

Understanding biopsy results and the Gleason score

If cancer is found, the biopsy report includes a Gleason score, which describes how abnormal the cancer cells look under a microscope. The score ranges from 6 to 10. A score of 6 means the cancer cells look fairly normal and grow slowly. A score of 10 means the cells look very abnormal and are likely to grow fast. Doctors use the Gleason score along with PSA level and the amount of cancer in the biopsy samples to decide how urgent treatment is.

Some men with low Gleason scores (6 or 7) and low PSA levels have what is called active surveillance instead of immediate surgery or radiation. This means regular PSA tests and sometimes repeat biopsies to watch the cancer over time. Many slow-growing prostate cancers never cause harm, so active surveillance avoids the side effects of treatment in men who may not need it.

Imaging tests to see if cancer has spread

If a biopsy shows cancer, your doctor may order imaging to check whether it has spread beyond the prostate. Common tests include a bone scan (to look for spread to bones), a CT scan (to check the pelvis and abdomen), or an MRI. The type and number of imaging tests depend on your Gleason score, PSA level, and how many biopsy samples contained cancer.

Men with low-risk cancer (low Gleason score, low PSA, cancer in few biopsy samples) often skip imaging because the chance of spread is very small. Men with high-risk features get more extensive imaging. These tests help your doctor and you decide whether treatment should focus on the prostate alone or include the surrounding area.

Who should be screened and when

Screening recommendations vary by age and risk. The American Cancer Society suggests that men have a conversation about screening starting at age 50 if they are at average risk, at age 40 to 45 if they have a family history of prostate cancer, and at age 40 if they are Black (because prostate cancer is more common and often more aggressive in Black men). The U.S. Preventive Services Task Force recommends shared decision-making for men ages 55 to 69 and suggests against routine screening for men 70 and older.

These are starting points for conversation, not rules. Your doctor will consider your overall health, life expectancy, and personal values. A man with a serious heart condition or limited life expectancy may not benefit from screening, because prostate cancer often grows slowly and may never cause symptoms or death.

What PSA levels mean and why they vary

A normal PSA is generally considered below 4 nanograms per milliliter (ng/mL), but this cutoff is not absolute. Some men with PSA below 4 have cancer, and some with PSA above 4 do not. PSA rises with age—a 70-year-old man might have a higher normal PSA than a 50-year-old. PSA also rises temporarily after ejaculation, vigorous exercise, or a urinary tract infection, so doctors often wait a few weeks before rechecking if a result is borderline.

Race and family history affect PSA levels too. Black men tend to have higher PSA levels at baseline and higher prostate cancer risk. Men with a father or brother who had prostate cancer may have higher PSA levels even without cancer. These factors are why your doctor interprets your PSA in context rather than as a simple number.

Frequently Asked Questions

Does a high PSA always mean I have prostate cancer?

No. A high PSA can come from cancer, but also from an enlarged prostate, infection, or recent ejaculation or exercise. Your doctor will usually repeat the test and may order imaging before recommending a biopsy. Many men with high PSA never develop cancer.

Is a prostate biopsy painful?

The biopsy is done with local anesthetic, so you should feel pressure and possibly a brief sharp sensation but not severe pain. Afterward, mild discomfort and blood in urine or stool are common for a few days. Serious complications are rare.

What if my biopsy shows cancer but my doctor recommends watching it instead of treating it?

Active surveillance means your cancer is low-risk—slow-growing and unlikely to spread. Regular PSA tests and sometimes repeat biopsies catch any change. Many men never need treatment. This approach avoids surgery or radiation side effects when they may not help you live longer.

Can I refuse screening even if my doctor recommends it?

Yes. Screening has benefits and harms. Some men find early detection reassuring; others worry about false alarms and unnecessary biopsies. Your values and preferences matter. A good conversation with your doctor should help you decide what is right for you.