Yes, the prostate is an organ. Specifically, it’s a small glandular organ, meaning it produces and secretes fluid as its primary job. In biological terms, any structure made of distinct tissues that performs a specific function qualifies as an organ, and the prostate checks every box. It sits below the bladder, surrounds part of the tube that carries urine out of the body (the urethra), and produces roughly 25% to 30% of the fluid in semen.
Why It’s Called Both a Gland and an Organ
You’ll see the prostate referred to as a “gland,” an “organ,” or sometimes “the prostate gland” interchangeably. This isn’t contradictory. A gland is simply a type of organ whose job is to produce and release a substance. Your thyroid, pancreas, and adrenal glands are all organs too. The prostate belongs to the same category: it’s an organ of the male reproductive system that functions as a gland.
Its primary output is a milky fluid rich in nutrients like zinc, citrate, calcium, and fructose. This fluid mixes with sperm from the testicles and additional fluid from the seminal vesicles to form semen. The nutrients in prostatic fluid nourish sperm and give them the energy they need to swim, making the prostate essential to fertility.
Size, Location, and Structure
A healthy adult prostate weighs about 25 grams, roughly the size of a walnut. It sits directly below the urinary bladder and in front of the rectum, which is why doctors can feel it during a rectal exam. Because it wraps around the upper portion of the urethra, any swelling in the prostate can squeeze that tube and affect urination.
The prostate has five lobes: anterior (front), posterior (back), two lateral lobes (one on each side), and a median lobe in the middle. It also produces a protein called PSA (prostate-specific antigen), which is mostly found in semen but circulates in small amounts in the blood. PSA blood levels are sometimes used as part of prostate health screening, though there’s no single cutoff number that separates “normal” from “abnormal.”
How the Prostate Changes With Age
The prostate is one of the few organs that keeps growing throughout a man’s life. This gradual enlargement, called benign prostatic hyperplasia (BPH), is extremely common and not cancerous. About 50% of men between ages 51 and 60 have some degree of BPH. That figure climbs to 70% for men in their 60s and around 80% for men over 70.
Because the prostate surrounds the urethra, this growth often leads to urinary symptoms: a weak stream, needing to urinate more frequently (especially at night), difficulty starting, or feeling like the bladder doesn’t empty completely. These changes are a normal part of aging for most men, though the severity varies widely.
Common Prostate Conditions
Beyond age-related enlargement, the prostate can develop inflammation known as prostatitis. There are four recognized types. Chronic prostatitis, also called chronic pelvic pain syndrome, is the most common. It causes pain lasting three months or longer in the area between the scrotum and anus, the lower abdomen, lower back, or penis. Pain during or after ejaculation is another hallmark symptom.
Acute bacterial prostatitis comes on suddenly with fever, chills, body aches, and burning during urination. It’s less common but more immediately serious. Chronic bacterial prostatitis causes recurring urinary tract infections with similar but less intense symptoms. The fourth type, asymptomatic inflammatory prostatitis, produces no noticeable symptoms at all and is typically discovered incidentally during testing for other conditions.
Screening and Risk Factors
Prostate cancer is one of the most common cancers in men, which is why screening conversations come up as men age. The U.S. Preventive Services Task Force recommends that men aged 55 to 69 make an individual decision about PSA screening after discussing the benefits and limitations with their doctor. Men 70 and older are generally not recommended for routine screening.
Risk factors influence when that conversation should happen. African American men face a higher risk of developing prostate cancer and dying from it. A family history of prostate cancer also raises risk. Both the American Urological Association and the American Cancer Society have their own guidelines, so screening timelines can vary depending on which recommendations your doctor follows and your personal risk profile.