When you notice blood in urine, it can feel alarming. While several conditions might cause this symptom, some sexually transmitted infections (STIs) are directly linked to blood appearing when you urinate. 

Understanding which infections could be responsible helps you seek the right treatment quickly.

What is defined as blood in urine?

Before getting into the specific infections, it is important to know what blood in urine means.

Medically, the presence of blood in urine is called haematuria. Sometimes, the blood is clearly visible, while in other cases, it can only be detected through laboratory testing. Blood may appear pink, red, or even brown depending on the amount and how long it has been present.

If you spot blood while passing urine, it is not something you should ignore. Whether the cause is an STI or another medical issue, you must get checked by a healthcare professional promptly.

Which sexually transmitted infections can cause blood in urine?

Certain infections are more likely than others to lead to blood in urine. Below are the main ones:

Chlamydia

Chlamydia is one of the most common STIs. This bacterial infection can affect the urethra, causing inflammation. When the urethra is inflamed, you might experience pain while urinating, an urgent need to urinate, and sometimes blood in urine.

Chlamydia often shows no symptoms at all, especially in the early stages. This is why regular testing is vital if you are sexually active, even if you feel healthy.

Gonorrhoea

Another common STI that can cause blood in urine is gonorrhoea. Like chlamydia, gonorrhoea can infect the urethra, leading to a condition known as urethritis. Inflammation from urethritis can cause bleeding, discomfort, and a burning sensation when you urinate.

In women, gonorrhoea can also affect the cervix, while in men, it might cause swelling of the testicles if left untreated.

Genital herpes

Although genital herpes is better known for causing painful blisters and sores, it can also lead to blood in urine. This happens when sores appear on or near the urethra, irritating the area and making urination painful and bloody.

Herpes is caused by the herpes simplex virus (HSV), and once contracted, the virus remains in the body for life, with symptoms flaring up from time to time.

Trichomoniasis

Trichomoniasis is a lesser-known STI but can still cause significant symptoms. It is a parasitic infection that affects both men and women. Inflammation of the urinary tract is common with trichomoniasis, leading to burning sensations during urination and sometimes blood in urine.

Unlike bacterial infections, trichomoniasis needs specific medication to clear up, so getting a correct diagnosis is essential.

Why do some STIs lead to blood in urine?

When infections target your urinary tract or genital area, they cause inflammation and irritation. Inflammation can weaken tiny blood vessels, leading to bleeding. If these blood vessels are located near the urethra or within the urinary tract, this blood can end up in your urine.

Infections like chlamydia and gonorrhoea attack the lining of the urethra, causing direct damage. Meanwhile, conditions like herpes irritate external tissues but can still affect urination if sores are located close to the urethral opening.

Other symptoms to watch for

If you notice blood in urine, you might also experience other symptoms linked to STIs, such as:

Noticing any of these signs alongside blood in urine increases the chance that an STI could be the cause.

What to do if you notice blood in urine

If you see blood in urine, it is crucial not to delay seeking help. Here are the steps you should take:

1. Book an appointment quickly

Contact your GP or visit a sexual health clinic as soon as possible.

2. Be honest during your consultation

Explain all your symptoms clearly and mention any potential exposure to STIs. This helps your healthcare provider choose the right tests.

3. Get tested

Testing often includes a urine sample, blood tests, and possibly swabs. These tests will help identify whether an STI is causing the issue.

4. Follow treatment advice

If an STI is confirmed, your doctor will prescribe appropriate medication. Always finish your full course of treatment, even if symptoms disappear early.

How to prevent STIs that cause blood in urine

Preventing the spread of STIs helps reduce your risk of seeing blood in urine. Here are some simple steps you can take:

By staying aware and proactive, you can lower your chances of encountering serious infections and protect your long-term health.

Act promptly and seek medical advice

Spotting blood in urine is never something you should ignore. Although STIs like chlamydia, gonorrhoea, herpes, and trichomoniasis can be common causes, only proper medical testing can identify the real issue.

Early detection and treatment are key to avoiding complications. If you notice symptoms, act promptly and seek professional care to safeguard your health.

Related read: Can A UTI Cause Blood In Urine?