The prostate

The prostate gland produces semen. It is situated close to the tube, which is called the urethra.

The prostate

The prostate is a small gland about the size of a walnut. It is divided into 2 lobes and surrounded by an outer layer called the capsule. The prostate gets bigger as you get older.

The prostate is below the bladder, surrounding the first part of a tube called the urethra. The urethra carries pee (urine) from the bladder to the penis. The same tube also carries semen, which is the fluid containing sperm. Just behind the prostate is the back passage (rectum). There are also lymph nodes (sometimes called glands) near the prostate.

The prostate contains muscle tissue and glandular tissue. Glandular tissue releases (secretes) certain substances.


Male reproductive system
Image: Male reproductive system

What does the prostate do?

The prostate produces a fluid that mixes with sperm from the testicles to make semen. This fluid is stored in 2 tube-shaped glands called the seminal vesicles. They are found just behind the bladder. During sex, the muscle tissue helps force (ejaculate) prostate fluid and sperm into the urethra.

The sex hormone testosterone is made by the testicles. It controls how the prostate works. Testosterone is responsible for things like sex drive, getting an erection, and muscle development.

The prostate also produces a protein called prostate-specific antigen (PSA). This helps to make semen more watery. A blood test can measure PSA. This is called a PSA test. Doctors use it to help diagnose different prostate problems, including cancer.

If you are a trans woman

People who have a prostate include men, transgender (trans) women and people assigned male at birth. If you are a trans woman and have had genital gender-affirming surgery as part of your transition, you will still have a prostate. 

Prostate Cancer UK has detailed information about trans women and prostate cancer.

The LGBT Foundation can also give you confidential advice and support. You can also talk to one of our cancer support specialists.

About our information

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    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editors, Dr Jim Barber, Consultant Clinical Oncologist and Dr Ursula McGovern, Consultant Medical Oncologist.

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