Causes

Semen consists of sperm and fluids released by the prostate and other glands. The fluids, also called ejaculate, join the sperm as they pass through a series of tubes to the urethra for ejaculation. A number of things can break blood vessels along this route or along the urinary route to the urethra. Broken vessels then leak blood into the semen, urine or both.

Your doctor will ask if you've had prostate surgery or a prostate biopsy recently, since these procedures can cause blood in semen for several weeks afterward.

Most often, no cause can be found for blood in semen. In some cases, particularly among men under age 40, infection is a possible cause. Infection is usually accompanied by other signs and symptoms, such as painful urination.

Severe or recurrent blood in semen and blood in semen in men age 40 and older might, in rare cases, be a warning sign for conditions such as cancer. As a result, a more careful evaluation might be needed. But the risk is low. In follow-up studies of men, mostly over 40, who had blood in their semen, prostate cancer developed in between 4 and 6 percent of participants.

Possible causes of blood in semen:

• Brachytherapy
• Chlamydia trachomatis
• Epididymitis (testicle inflammation)
• Excessive sexual activity or masturbation
• External beam radiation for prostate cancer
• Genital herpes
• Gonorrhea
• Hemophilia
• Orchitis (inflamed testicle)
• Prolonged sexual abstinence
• Prostate biopsy
• Prostate cancer
• Prostatitis (infection or inflammation of the prostate)
• Testicular trauma
• Vasectomy

Rare causes of blood in semen:

• Amyloidosis (buildup of abnormal proteins in your organs)
• Benign growths (cysts, polyps) in the bladder, urethra or prostate
• Schistosomiasis
• Testicular cancer
• Tuberculosis
• Warfarin side effects