Merck Manual

Please confirm that you are not located inside the Russian Federation

Quick Facts

Benign Prostate Hyperplasia (BPH)


The Manual's Editorial Staff

Last full review/revision Sep 2019
Click here for the Professional Version
Get the full details
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Topic Resources

What is the prostate?

The prostate is a gland located between a man’s bladder and penis. The tube (urethra) that carries urine from the bladder and out the penis runs right through the middle of the prostate.

The prostate makes fluid that helps keep sperm healthy. Nearly all the fluid that a man ejaculates during sex is made by the prostate.

The prostate is the size of a walnut in young men, but gets bigger as you get older.

What is BPH?

Hyperplasia means your prostate grows bigger (enlarges). Benign means the growth in size isn't cancer. An enlarged prostate can squeeze the tube that carries urine (urethra) and make it harder to urinate (pee).

  • BPH is common after age 50

  • Doctors diagnose BPH by inserting a gloved finger into your rectum (the end of your digestive tract where stool [poop] is stored) and feeling the prostate (a rectal exam)

  • You may have tests to see how well your urine is flowing and other tests to make sure you don't have prostate cancer

  • You may not need treatment for BPH

  • If your symptoms bother you a lot, you may need to take medicine or have surgery

What causes BPH?

Doctors aren’t sure what causes BPH. It's probably due to changes in hormones as you get older.

What are the symptoms of BPH?

BPH blocks the flow of urine, so men can have these symptoms:

  • Trouble starting urination

  • Having a smaller and weaker flow of urine

  • Dribbling at the end of urination

Because the flow of urine is blocked, your bladder doesn't empty completely and you may:

  • Feel like urination isn't complete

  • Need to urinate more often, especially at night

  • Feel an urgent need to urinate

  • Develop a bladder infection

Sometimes the flow of urine is completely blocked so you can't urinate (pee) at all (a condition doctors call acute urinary retention). When this happens, your bladder quickly fills with urine and becomes extremely painful. It'll hurt so much you'll want and need to see a doctor right away.

What Happens When the Prostate Gland Enlarges?

In benign prostatic hyperplasia, the prostate gland enlarges. Normally the size of a walnut, the prostate gland may become as large as a tennis ball. The enlarging prostate gland squeezes the urethra, which carries urine out of the body. As a result, urine may flow through more slowly, or less urine may flow through.

What Happens When the Prostate Gland Enlarges?

How can doctors tell if I have BPH?

Your doctor will ask about your symptoms and do a rectal exam:

  • A doctor inserts a gloved finger into your rectum (the end of your digestive tract where stool [poop] is stored)

  • Your doctor is able to feel your prostate during the exam

  • If you have BPH, your prostate will feel large and smooth to the doctor

If you're having a lot of trouble urinating (peeing), your doctor may do a uroflowmetry test. In this test, you urinate into a device that measures the amount of urine and how fast it flows. After the uroflowmetry test, doctors do an ultrasound to see how much your bladder emptied. Ultrasound uses sound waves to measure the exact amount of urine inside your bladder.

Prostate cancer also makes the prostate grow larger. Doctors need to tell whether your symptoms are from BPH or prostate cancer. Sometimes cancer makes a hard lump that the doctor can feel in your prostate, but it often does not. So usually, the doctor does:

  • A blood test called a PSA level

Depending on the PSA level, your exam, and other things, the doctor may recommend you have:

  • A prostate biopsy

In a prostate biopsy, the doctor uses a hollow needle to take samples of tissue from your prostate. First, the doctor puts an ultrasound probe in your rectum. The ultrasound pictures show the doctor where to guide the needle. The doctor first injects some numbing medicine and then takes several samples.

How do doctors treat BPH?

Doctors don’t usually treat BPH unless the symptoms are bothering you or causing infections. In such cases, your doctor may give you medicines.

Some medicines relax certain parts of the prostate and bladder to improve urine flow. Other medicines shrink the prostate. If medicines don’t work, you may need surgery.

In the surgery, called a TURP (which stands for transurethral resection of the prostate), the doctor:

  • Puts a scope up your penis all the way to the prostate

  • Uses instruments or a laser to remove part of the prostate

Most often, the TURP procedure will relieve your symptoms. But there is a small risk you will leak urine afterwards or have trouble getting an erection.

If you have a sudden attack where you can't urinate at all (acute urinary retention), you will need a catheter. A catheter is a soft rubber tube that the doctor puts through your penis and into the bladder. The catheter lets the urine out. You will usually have to keep the catheter in for several days.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version

Also of Interest


View All
Benign Prostatic Hyperplasia
Benign Prostatic Hyperplasia
The prostate is a small, round gland of the male reproductive system that is located in front...
The Epididymis
The Epididymis