Blood in semen – why it happens and what to do

2nd April, 2025 • 5 min read

It can be worrying, but seeing blood in your semen isn’t usually a sign of anything serious. While it often goes away on its own, it’s important to speak to a doctor, so they can check what’s causing it and if you need treatment.

Dr Maria Reza
Reviewed by
Medically reviewed

Noticing blood in your semen can be scary, but in most cases it isn’t a sign of a serious medical condition.

However, blood in your semen is not ‘normal’, and you should get it checked by a doctor. Rarely, it can be a sign of prostate cancer.

Medically known as ‘hematospermia’ or ‘hemospermia’, blood in your semen can commonly be caused by a burst blood vessel or an infection.

If your doctor finds a cause for blood in semen, this may need treating. But in many cases, symptoms will go away without treatment.

What are the symptoms?

Blood in your semen can be pink, red, or brown in color. You may also notice small lumps (clots) in the blood.

Depending on the cause, you may only notice the blood once, or you may see it for several days or weeks.

If an infection or other health issue is causing the blood, you may get other symptoms, such as:

  • needing to pee (urinate) more than usual
  • fever or chills
  • pain when you pee, poop, or ejaculate
  • blood in your pee
  • swelling or tenderness in your groin or the sack that contains your testicles (scrotum)
  • pain in your lower back.

What causes blood in semen and who is affected?

The most common causes of blood in semen are inflammation and infection, including urinary tract infections (UTI) and sexually transmitted infections (STIs).

Other possible causes include:

  • a small blood vessel bursting when you ejaculate
  • a long period of not having sex, having sex that lasts a long time, or masturbating a lot
  • an injury to your reproductive or urinary system
  • a recent medical procedure or test, such as a prostate biopsy, resection of the prostate (TURP), a cystoscopy, or a vasectomy
  • a prostate condition – such as inflammation (prostatitis), a cyst, or an enlarged prostate
  • a blood problem, such as a clotting disorder
  • treatment for prostate cancer.

Rarely, prostate or testicular cancer can cause blood in your semen – though it’s rare for this to be the first symptom.

In some cases it’s not clear what causes blood in semen.

Blood in semen is most common in males under 40.

It’s difficult to know exactly how common it is, because people don’t necessarily look for or notice blood in their semen – or don't feel comfortable to see a doctor about it if they do.

When to see a doctor and getting diagnosed

If you see blood in your semen, speak to a doctor. While it’s probably nothing to worry about, they can check if it’s caused by an infection or another condition that needs treatment.

Your doctor will take your medical history and ask questions, such as how long you’ve had blood in your semen, if you have any other symptoms, and if you’re taking any medication.

They may do a physical exam, checking your genitals for lumps, tenderness, or redness. Your doctor may also carefully put a gloved finger into your bottom (rectum) to feel your prostate.

Your doctor can order tests to see if an infection or another health condition is causing blood in your semen, which may include:

  • urine tests
  • blood tests
  • STI tests
  • ultrasound or MRI scan of your prostate, scrotum, or pelvis
  • cystoscopy – when a thin tube with a small camera attached is inserted into your pee tube (urethra) to look at your bladder.

What are the treatments?

In many cases, blood in semen clears up on its own within a few weeks and doesn’t require treatment.

However, if something is found to be causing it, this may need treatment.

If it’s caused by an infection or inflammation – such as an STI or prostatitis, you may be prescribed antibiotics.

If you have a cyst on your prostate, this can be treated with minor surgery, where a doctor gently inserts a needle to drain it.

When a more serious health condition – such as a blood-clotting disorder or cancer – is causing blood in your semen, your doctor will refer you to a specialist for treatment.

Self-care tips

If a prostate or urinary infection has caused blood in your semen, you can look after yourself by:

  • taking over-the-counter painkillers – check with your doctor before taking anything alongside prescription medication
  • drinking plenty of fluids to stay hydrated
  • eating high-fiber foods to help you poop more easily.

If you have an injury (for example from vigorous sex), it’s a good idea to avoid sex or masturbation for a few days to allow it to heal.

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.