Seeing blood in your semen can be startling. It’s uncommon, and it rarely signals a serious problem, especially in men under the age of 40. Blood in the semen (hematospermia) often doesn’t last long, as it’s usually a self-resolving problem.

The amount of blood in your semen can vary from a small drop to enough to give your semen the look of blood. How much blood is in your semen will depend on the cause of your bleeding. You might also experience:

Semen passes along a series of tubes on the way to the urethra for ejaculation. Any number of things can cause blood vessels along this path to break and leak blood into the semen.

In many cases, the exact cause for blood in the semen is never determined. Most cases of blood in the semen are not serious, especially if you’re 40 or younger. Below are some of the possible causes of bloody semen that your doctor might investigate.

Inflammation

Inflammation of the seminal vesicles is a common cause of bloody semen. Inflammation of any gland, duct, tube, or organ involved in the male genitals can cause blood in your semen. This includes:

  • Prostatitis (inflammation of the prostate gland), which can cause pain, urination problems, and sexual dysfunction.
  • Epididymitis (inflammation of the epididymis, or the coiled tube in the back of the testicle where sperm is stored), most often caused by a bacterial infection, including sexually transmitted infections (STIs) such as herpes, gonorrhea, or chlamydia. Symptoms include red or swollen scrotum, testicle pain and tenderness on one side, discharge, and painful urination.
  • Urethritis (inflammation of the urethra), which can cause pain while urinating, itching or burning near the opening of the penis, or penile discharge.

Inflammation can also be caused by irritation from calculi (stones) in the prostate, seminal vesicles, bladder, or urethra.

Infections

Just as with inflammation, infections in any gland, duct, tube, or organ involved in the male genitals can cause blood in the semen.

STIs (commonly referred to as sexually transmitted diseases, or STDs), such as chlamydia, gonorrhea, or herpes, can also cause blood in semen. Infections caused by viruses, bacteria, or fungi can also lead to this condition.

Obstruction

If ducts like the ejaculatory duct are blocked, surrounding blood vessels can dilate and break. If your prostate is enlarged, it can put pressure on your urethra, which can cause bloody semen.

Tumors

Benign polyps or malignant tumors in the prostate, testicles, epididymis, or seminal vesicles could lead to blood in your semen.

Vascular abnormalities

Vascular abnormalities in the male genitals, such as vascular cysts, could explain the blood you’ve seen in your semen.

Other factors

Conditions that affect your whole body can cause blood in your semen. These include hypertension (high blood pressure) and hemophilia (disorder that leads to easy and excessive bleeding). Other possibilities include leukemia and chronic liver disease.

Trauma/medical procedures

Physical trauma, such as being hit in your testicles while playing sports, can lead to blood in your semen. Trauma can cause blood vessels to leak, and that blood may leave your body in semen. A medical procedure like a prostate exam or biopsy or a vasectomy can cause blood in your semen.

As a rule of thumb, you should see your doctor for blood in the semen if you have a family or personal history of cancers or STIs. Your age can also serve as a guideline.

If you’re over 40

Men ages 40 and over have a higher risk of developing illnesses like prostate cancer. Because of this, you should tell your doctor any time you see blood in your semen. Your doctor will want to check for the cause of the blood as soon as possible.

If you’re under 40

If you’re under the age of 40 and don’t have any symptoms other than bloody semen, wait and see if the blood goes away on its own.

If your semen continues to be bloody or if you start experiencing additional symptoms like pain or a fever, make an appointment with your doctor. They might perform a prostate exam or analysis of your semen and urine to determine the source of the blood.

When you visit your doctor, they’ll first need to determine the cause of the blood in the semen. Things they may do include:

  • Physical examinations. Your doctor may examine you for other symptoms, including swollen testicles, redness, or other visible signs of infection or inflammation.
  • STI tests. Through tests including blood work, your doctor will check to make sure you don’t have STIs that could be causing the bleeding.
  • Urinalysis. This can help detect bacterial infections or other abnormalities in your urine.
  • PSA testing, which tests for prostate-created antigens and evaluates the health of the prostate.
  • Screening tests like ultrasounds, CTs, and MRIs, which can help locate obstructions.
  • Transrectal ultrasound, which uses a transducer pen to look for tumors and other abnormalities around the prostate.

Men older than age 40 may be referred to a urologist for further evaluation. Those under the age of 40 may also need to see a urologist if their symptoms continue despite treatment.

Depending on the cause of the blood in your semen, you might be able to treat yourself at home. If the underlying cause requires medical treatment, your doctor will work with you to decide the course that is right for you.

Treatment at home

If you have blood in your semen as a result of a trauma, simply resting and allowing your body to heal may help. If you also have swelling in your groin, you can apply ice to the area for 10 to 20 minutes at a time, but no longer than that.

Most cases of hematospermia resolve on their own. Keep an eye on your symptoms and alert your doctor if they get worse or persist for longer than one month.

Medical treatment

If the blood in your semen is caused by an infection, your doctor will prescribe antibiotics. Anti-inflammatory medications are available if swelling alone is the cause.

If the blood in your semen is caused by a blockage in your genitourinary tract, surgery may be necessary. Potential surgeries include removal of a bladder stone that’s obstructing the urinary tract or removal of tumors.

If cancer is causing the blood in your semen, your doctor will probably refer you to a specialist (oncologist) who will determine the best treatment.

As startling as blood in your semen may be, it’s important to remember that in most cases it’s not a symptom of a serious condition.

If you continue to experience bloody semen, ask your doctor for a referral to a urologist. This specialty doctor can help treat any serious underlying causes of blood in your semen.