Hematospermia (sometimes spelled haematospermia) refers to blood in the semen. Men may notice that their semen is bloodstained, pink, or reddish-brown. But sometimes the blood is microscopic and cannot be seen at all.

When sperm is made by the testes, it travels to the seminal vesicles, where it mixes with other ejaculatory fluids to form semen. From there, the semen goes to the ejaculatory ducts and is expelled from the penis when a man reaches orgasm. Bleeding can occur at any point along this route.

The idea of blood in the semen can be worrisome, but most of the time, it is not a problem. Hematospermia often goes away on its own.

Still, it is important for men who find blood in their semen to see a doctor, especially if they have other symptoms, such as

• blood in the urine
• pain with urination, ejaculation, or bowel movements
• swelling in the scrotum or groin
• fever or chills.

Some causes of hematospermia include the following:

• Sexually-transmitted infections such as chlamydia, genital herpes, and gonorrhea might cause blood in the semen.
• Prostate conditions. A man might discover blood in his semen if he has had a prostate biopsy or if he has an enlarged prostate. Prostatitis (inflammation of the prostate) is another possible cause.
• Brachytherapy is a type of radiation therapy used to treat prostate cancer. Small radioactive seeds are planted into the prostate gland and, for some men, this results in hematospermia.
• Epididymitis is inflammation of the epididymis, the tube that stores sperm before it mixes with ejaculatory fluid.
• Urethritis is inflammation of the urethra, the tube from which urine and semen leave the body.
• Injury or trauma to the reproductive system. There could happen in a variety of ways, such as car accident, a sports injury, or vigorous sex.
• Vasectomy. Some men experience bleeding for a short time after this procedure.
• Cancer. Very rarely, hematospermia is a sign of testicular or prostate cancer.

Some men find blood in their semen if sex is interrupted or if they haven’t had sex for a long time.

If blood in the semen is the only symptom, treatment is probably not necessary. Men should still see a doctor, however.

If a man has other symptoms, a urologist may conduct tests to determine the cause. Tests may include semen analysis, urine analysis, x-rays, ultrasound, or rectal examination. Once an underlying condition is found, it can be treated and, in most cases, blood in the semen will clear up. For example, if a man has an infection, he may need to take antibiotics.