What Causes Blood in Semen? Diagnosis, Treatment and More

By Frank DiVincenzo, MD
Medically reviewed checkmarkMedically reviewed
May 17, 2022

Noticing blood in your semen can be an unsettling surprise.

However, typically, it is not something to worry about as it usually resolves on its own. 

If you see blood in your semen and are under 40 years of age, you should monitor yourself for a few days to make sure it resolves.

You only need to seek treatment if it doesn’t go away. However, people over 40 should consider letting their medical provider know, as they are at risk for other complications.

This article goes over what blood in your semen is, how common it is, and what some potential causes could be. We’ll also discuss the diagnosing of blood in your semen and what treatments are available.

Lastly, you’ll learn when to reach out to your medical provider. 

What Is Blood in Semen?

Blood in the semen is called hematospermia.

The amount of blood in your semen may be microscopic and difficult to see or there could be enough blood to turn it pink or red. 

If this is causing you some stress, you are not alone.

Seeing blood in the semen is known to cause anxiety for the person experiencing it and their sexual partner(s).

In most cases, though, the cause is harmless, and it quickly resolves on its own.

However, a person over 40 years of age, or someone who has other risk factors, should have a thorough examination. 

Concerned about blood in semen? Chat with a medical provider through K Health.

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How Common Is It?

It is difficult to say how common it is for people to have blood in their semen because usually, it goes unnoticed. 

One study reports that one in every 5,000 new patients to a urologic clinic has this complaint.

Most of those patients were between 30-40, but people younger or older can also experience it.  

Let’s go over some potential causes of blood in semen could be. 

Potential Causes of Blood in Semen

There are several reasons why you may have blood in your semen.

Most of them are not a problem, and in 70% of the cases, the cause is not found. 

Inflammation, infection, and injury are considered the most likely causes of blood in your semen

Inflammation

Inflammation is a frequent cause of blood in the semen. Potential causes could be from:

Prostatitis: The prostate is a walnut-shaped gland of the reproductive system. Bacterial infection is sometimes the cause of inflammation and can be painful. Several treatments are available depending on what the underlying cause is. 

Urethritis: Urethritis is a bladder infection that is only in the urethra. The condition can cause inflammation that may cause blood in the semen.  

Infection

Infections that can cause blood in the semen can be due to:

  • Human immunodeficiency virus (HIV)
  • Cytomegalovirus: a common virus 
  • Herpes: a common sexually transmitted infection (STI)
  • Chlamydia trachomatis: another common STI
  • Enterococcus faecalis: a common bacteria of the GI tract

Injury

A common cause of blood in the semen is an injury to the pelvis, perineum, or genitals.

Many situations can cause damage, including a car accident or sports injury. 

Rigorous or excessive sexual activity has also caused bloody semen. 

Medical procedures

The most common medical procedure to cause bloody semen is a prostate biopsy.

In a study, more than 80% of people reported having blood in their semen for up to four weeks after their biopsy procedure.

Typically, these biopsies check for prostate cancer.

Other medical procedures that can cause hematospermia:

  • Cystoscopy: A cystoscopy is a procedure in which a small camera is inserted into the bladder. This procedure checks for problems in the bladder and fixes them. It is done with a local anesthetic and doesn’t require a hospital stay. 
  • Transurethral resection of the prostate (TURP): This is a medical procedure to remove part of the prostate, usually because of prostate enlargement that makes urinating difficult. You are under anesthesia for the procedure and typically require hospitalization for a few days. There can be blood in the urine and potentially the semen for a few days after.  

Obstructions

Several things can cause an obstruction:

  • Cysts: Seminal vesicle cysts have sometimes caused hematospermia. However, these cysts only occur in 0.005% of people, so the occurrence is infrequent. Cysts can also obstruct the ejaculatory duct, though this is also very rare. 
  • Polyps: On rare occasions, polyps (an irregular growth of fibrous tissue) can grow in the urethra, causing a blockage and possible blood in the urine and semen.
  • Strictures: A stricture is when there is a narrowing of a tube. Sometimes scar tissue growing around the urethra can create a stricture, leading to some bleeding.
  • Benign prostate hyperplasia (BPH): A condition in which the prostate becomes enlarged, BPH can cause the area around the urethra to become more narrow and potentially cause blood in the semen.

Tumors

Tumors can arise in the prostate, testes, and seminal vesicles.

Although rare, tumors can cause blood in the semen. It is thought that the blood vessels feeding the tumors may be fragile and easily broken with ejaculation. 

Other tumor symptoms include a lump or painful swelling in the scrotum area.

If you believe you have a tumor, call your medical provider right away. 

Ruptured blood vessels

The pelvic area has many small vessels.

Like a bloody nose after sneezing because of a minor blood vessel break, blood can be in the semen because of a small blood vessel breaking with ejaculation. 

Prostate cancer

The prostate is a gland that sits around the urethra. Cancer of the prostate can sometimes lead to blood being in the semen. 

Other symptoms include:

Vascular abnormalities

There are many blood vessels in the genital area of the body and sometimes, an abnormality of blood flow may cause blood to enter the semen. 

Typically, blood vessels and seminal vessels are entirely separate from each other.

However, there have been rare cases of the vessels fusing and allowing blood to flow into the semen at ejaculation. 

A hemangioma is a rare and non-cancerous tumor that can grow in veins.

In several cases, these have caused blood to enter the semen.  

Other causes

Very high blood pressure has been known to cause hematospermia

Clotting disorders like hemophilia, when the blood doesn’t clot correctly, have also been known to cause the semen to have blood in it.   

Diagnosing the Cause

If blood in your semen is an ongoing issue or you are over 40, seeing your medical provider is a good idea.

Initial evaluation

Initially, your medical provider will want to review what medications you are taking and go over your medical history. 

They will ask if you have pain in your genital area or pain with erection, penetration, and ejaculation.

They will also ask how long you have had these symptoms and if you’ve noticed any other issues. 

Your medical provider will also want to perform a physical exam of your genital area and check your vital signs for possible high blood pressure.

Diagnostic tests 

Your provider may order the following tests:

  • STI tests to check for possible infection
  • Urinalysis to see if the cause could be a bladder infection
  • PSA testing to check the health of your prostate
  • Condom test to verify the blood is yours; the medical provider will ask you to wear a condom during intercourse

Specialized tests

Your medical provider may refer you to a urologist who will order some specialized tests. 

  • Transrectal ultrasound to check all internal structures
  • CT or MRI exam for a more detailed look at potential structural abnormalities

Treatments

Even after a full work-up, sometimes the cause of the blood may not be known. If found, the treatment is based on the underlying condition. 

For an obstruction or other anatomical abnormality, surgery may be needed.

For an infection, you may be treated with antibiotics. 

For high blood pressure, taking an antihypertensive medication will lower your blood pressure and help stop blood in the semen. 

For coagulation disorders, treatment with an appropriate medication may be necessary.  

Prostate cancer has several treatments, including surgery, chemotherapy, radiation, hormonal therapy, and others. 

Concerned about blood in semen? Chat with a medical provider through K Health.

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When To Contact a Medical Provider

As a general rule, if you have a family history of prostate cancer or a personal history of an STI, it’s recommended to let your medical provider know of your bleeding. 

If the bleeding continues or you also start experiencing other symptoms like pain or a fever, be sure to let your medical provider know. 

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K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Frank DiVincenzo, MD

Dr. Frank DiVincenzo has been a physician with K Health since 2020. He grew up near Chicago, Illinois, but left the big city to go to college and then attend graduate school in Missouri. He received a Bachelor of Science in Mathematics and a Master of Science in Microbiology before graduating from the University of Missouri–Columbia School of Medicine.