Why is there blood in my semen?

Blood in semen – how serious is it?

If following ejaculation, you notice your semen is bright red, reddish-brown, or pink in colour, you're one of many who've experienced semen haematospermia - blood in your semen. As a one-off episode this is usually nothing to worry about, especially if you're relatively young and in good health.

However, even though in most cases the cause is relatively minor and temporary, never ignore it as there is a small chance that blood in semen can indicate a serious condition, such as prostate cancer or testicular cancer. As you get older, the chances of this remain small but do increase.

To help give an idea of what this symptom is more likely to be, we explore some of the more common causes behind the presence of blood in semen.

The most common cause of blood in semen

According to men's health specialist Dr Jeff Foster, a GP at H3Health, more than 90% of cases are caused by sexual activity. This is due to the rupturing of blood vessels which can occur during any form of sex, whether this be masturbation, any type of penetrative sex.

"This is very common," advises Dr Foster. "However, although an extremely rare cause, this could be a sign of testicular cancer." For this reason it's important to get checked out.

Your FAQs - why is there blood in my semen?

Fewer than 10% of cases are caused by something else happening in your body, and there are many possibilities. To explore these, Dr Foster answers the most frequently asked questions:

Can a UTI cause blood in semen?

"Potentially, yes," says Dr Foster. "Generally, healthy and fit men don't tend to get urinary tract infections (UTIs), so having a UTI can indicate that something else more significant is wrong in your body. So, if you have blood in your semen that you think or know is due to a UTI, don't assume that all else is okay. It's important that you get checked out by a doctor, especially if you're over 30 years of age."

Other types of infections may also cause blood in semen. For example, a sexually transmitted infection (STI) - such as chlamydia or gonorrhoea;or epididymitis, an infection of the tube at the back of your testicles.

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Can prostatitis cause blood in semen?

According to Dr Foster, this is also true. Prostatitis is where your prostate - a gland between your bladder and penis which produces part of your semen - becomes infected or inflamed. Like a UTI, prostatitis can cause pain in your testicles or penis, painful urination, more frequent urges to urinate, and blood in semen.

Can BPH cause blood in semen?

A benign prostatic hyperplasia (BPH), also known as prostate gland enlargement, also affects the prostate gland. However, Dr Foster believes this shouldn't be a cause of blood in your semen. While the prostate has become larger, benign means it's harmless and not angry or inflamed, unlike in prostatitis. The main symptoms are trouble with peeing and the inconvenience of needing to pee more frequently.

In many men, an enlarged prostate is a normal part of aging. By age, it affects around:²

• 8% of men in their 30s.

• 25% of men in their 50s.

• 33% in their 60s.

• 50% of men over 80 years of age.

Can a hernia cause blood in semen?

"No, hernias never directly affect the tubes that produce semen, but they can press against this region," Dr Foster says.

A hernia describes an organ or section of tissue that has pushed through a weak spot in surrounding tissue, causing a bulge in another part of your body. While this doesn't cause blood to seep into your semen, it can sometimes place pressure on your scrotum, resulting in scrotal and testicle pain.

Can kidney stones cause blood in semen?

"Definitely not," confirms Dr Foster. "Kidney stones travel through your kidneys, ureters, bladder, and urethra, and this pathway isn't connected to your testicles."

Like hernias, the pain of kidney stones can be felt nearby in the body. That's why some people with kidney stones experience testicle pain.

Further reading

1. American Cancer Society: Key statistics for prostate cancer.

2. Healthy Male: Prostate enlargement vs prostatitis vs prostate cancer - what's the difference?