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.

Related pages

Prostate cancer

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

References

Below is a sample of the sources used in our prostate cancer information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

C. Parker, E. Castro, K. Fizazi, et al. Prostate cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of Oncology, 2020, Volume 31, Issue 9, p1119-1134. Available from www.esmo.org/guidelines/genitourinary-cancers/prostate-cancer

National Institute for Health and Care Excellence (2019) Prostate cancer: diagnosis and management (NICE guideline NG131). Last updated December 2021 to include Risk stratification for localised or locally advanced prostate cancer. Available at www.nice.org.uk/guidance/ng131

Reviewers

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.

Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

use plain English
explain medical words
use short sentences
use illustrations to explain text
structure the information clearly
make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.