The prostate is a small gland found only in men (and people assigned male at birth) that sits just below the bladder and wraps around the urethra, the tube that carries urine out of the body. About the size of a walnut in younger men, its primary job is producing fluid that mixes with sperm to form semen. It’s one of those body parts most people never think about until something goes wrong, but understanding what it does and how it changes over time can help you recognize problems early.
Where the Prostate Sits
The prostate is tucked deep in the pelvis, directly beneath the bladder and in front of the rectum. Because it surrounds the urethra, any swelling or growth in the prostate can squeeze that tube and affect how easily urine flows. This location is also why doctors can feel the prostate during a rectal exam: the back wall of the gland sits right against the rectum.
The gland itself has distinct internal zones. The peripheral zone makes up over 70% of the glandular tissue and is the area where most prostate cancers develop. The central zone accounts for about 25% and surrounds the ducts that carry sperm from the testicles. A smaller transition zone sits closest to the urethra and is the region that tends to enlarge with age. Finally, a thick layer of non-glandular muscle and fibrous tissue covers the front surface like a shield.
What the Prostate Does
The prostate’s main role is reproductive. It produces a thin, milky fluid that makes up a significant portion of semen. This fluid contains enzymes (including prostate-specific antigen, or PSA) that thin semen after ejaculation so sperm can swim freely. It also contains a substance called spermine that helps sperm cells move. Without a functioning prostate, sperm would have a much harder time reaching and fertilizing an egg.
During ejaculation, the prostate contracts and pushes its fluid into the urethra, where it mixes with sperm and fluid from the seminal vesicles. The muscles of the prostate also help propel semen outward. At the same time, the gland acts as a valve, preventing urine from mixing with semen during ejaculation.
How It Changes With Age
In men in their 40s, the prostate typically measures around 28 milliliters in volume, roughly the size of that walnut comparison you’ve probably heard. By the time a man reaches his 60s, average volume grows to about 35 milliliters. The gland tends to lengthen more than it widens, especially after age 60. This growth is a normal part of aging driven by hormonal changes, but it can lead to problems when the expanding tissue presses against the urethra.
Three Common Prostate Conditions
Enlarged Prostate (BPH)
Benign prostatic hyperplasia, or BPH, is the most common prostate issue in older men. It simply means the number of cells in the prostate has increased, causing the gland to grow. Because the prostate wraps around the urethra, this growth can squeeze the urinary passage and create noticeable symptoms: needing to urinate more often (especially at night), a weak or stop-and-start stream, straining to begin urinating, or feeling like your bladder never fully empties. BPH is not cancer and does not increase your cancer risk, but it can significantly affect quality of life.
Prostatitis
Prostatitis is inflammation of the prostate, and it can strike men at any age. The acute bacterial form comes on suddenly with fever, chills, body aches, burning during urination, and pain in the lower abdomen or groin. A chronic version produces similar but milder symptoms that come and go over months. There’s also a form called chronic pelvic pain syndrome that causes persistent pain in the genital area or lower back along with urinary difficulties, even without a clear infection. Some men have inflamed prostates with no symptoms at all, discovered only through lab tests.
Prostate Cancer
Roughly 13.2% of men will be diagnosed with prostate cancer at some point in their lives. Most prostate cancers grow slowly and start in the peripheral zone of the gland. Early-stage prostate cancer typically causes no symptoms at all, which is why screening matters. When the disease advances locally, it can produce urinary symptoms, blood in the urine or semen, or persistent pain in the back, hips, or pelvis. The survival picture varies dramatically by stage: the five-year survival rate for cancer that remains localized to the prostate is essentially 100%, while cancer that has spread to distant parts of the body drops to about 40%.
Screening and PSA Testing
PSA is a protein naturally produced by the prostate, and a blood test can measure its levels. Higher PSA can signal cancer, but it can also rise from BPH, infection, age, and even factors like physical activity or ethnicity. That’s why PSA testing is not a simple pass/fail. It’s a starting point for conversation.
Current guidelines from the U.S. Preventive Services Task Force recommend that men ages 55 to 69 make an individual decision about PSA screening after discussing the potential benefits and trade-offs with their doctor. For men 70 and older, routine screening is generally not recommended. Black men face a higher risk of developing prostate cancer and dying from it, and men with a family history of the disease, particularly multiple close relatives, may want to start those conversations earlier. The task force encourages both groups to be informed about their elevated risk so they can decide what’s right for them.
Recognizing Urinary Symptoms
Doctors use a standardized questionnaire called the International Prostate Symptom Score to gauge how much prostate-related urinary issues are affecting your life. It measures seven specific symptoms: feeling like your bladder doesn’t empty completely, urinating less than two hours after you last went, a stream that stops and starts, difficulty holding it when you feel the urge, a weak stream, needing to push or strain, and waking up at night to urinate. Scores from 0 to 7 are considered mild, 8 to 19 moderate, and 20 to 35 severe. Tracking these symptoms over time helps determine whether treatment is working or if things are getting worse.
Diet and Prostate Health
What you eat appears to meaningfully influence prostate health over time. Diets rich in tomatoes and tomato-based products (which contain lycopene) are associated with lower prostate cancer risk. Even a modest increase of 2 milligrams of lycopene per day, about what you’d get from a few extra tablespoons of tomato sauce, is linked to a 1% risk reduction. Oily fish like salmon, sardines, and mackerel provide omega-3 fatty acids associated with lower rates of advanced prostate cancer. Cruciferous vegetables like broccoli and cauliflower show a protective effect, with as little as half a cup per day linked to lower recurrence risk. Garlic and onions eaten at least once a week are also associated with reduced risk.
On the other side, high intake of dairy products (especially whole milk), red and processed meats, eggs, and refined carbohydrates are all associated with increased prostate cancer risk. Consuming more than 1,500 milligrams of calcium per day and eating five or more eggs per week are linked to higher rates of aggressive disease. Obesity independently raises risk and worsens outcomes. Overall, the evidence consistently favors a plant-based dietary pattern: more vegetables, fruits, legumes, and fish, with less processed food and red meat.
Green tea drinkers who consume five or more cups daily show lower rates of advanced prostate cancer compared to those drinking less than one cup. Soy products also appear protective, with one large analysis finding a 26% reduction in risk among men with higher soy intake.