What causes blood in the urine?

Author: Alana Biggers, MD, MPH

Blood in the urine is a symptom of many common problems in males. The medical term for blood in the urine is hematuria.

In this article, learn about nine possible causes of hematuria in males, along with their additional symptoms and information on when to see a doctor.


In males, blood in the urine can result from any of the following:

1. Urinary tract infection

If a UTI affects the kidneys, it can cause pain in the back and sides of the body.

Urinary tract infections (UTIs) are a common cause of blood in the urine. Although they occur more frequently in women, men can also develop them.

Risk factors for UTIs in males include prostate problems and recent catheterization.

UTIs can occur when bacteria enter the urethra, which is the tube that carries urine from the bladder out of the body.

In addition to blood in the urine, symptoms of a UTI include:

  • urgent and frequent urination
  • pain or burning in the urethra
  • cloudy, strong-smelling urine

Rarely, a UTI can affect the kidneys. In this case, the infection tends to be more severe and may cause the following additional symptoms:

  • pain in the back, sides, and groin
  • nausea and vomiting
  • a fever and chills

2. Kidney and bladder stones

If the blood contains too little liquid and too much waste, the waste products can bind with chemicals in the urine, forming hard stones in the kidneys or bladder.

Often, the stones are small enough to pass through urination. Larger stones may remain in the kidney or bladder or get stuck elsewhere in the urinary tract.

Larger stones generally cause more noticeable symptoms, such as:

  • blood in the urine
  • lower back pain on either side
  • persistent stomach pain
  • nausea or vomiting
  • a fever and chills
  • cloudy or strong-smelling urine

3. Exercise-induced hematuria

Exercise-induced hematuria (EIH), also known as post-exertional hematuria, refers to blood in the urine that occurs after a person exercises.

Doctors are not sure what causes EIH, but it tends to be associated with high-intensity exercise, rather than the duration of exercise.

People who do not stay properly hydrated while exercising may also have an increased risk.

A 2014 study investigated the occurrence of EIH in a group of 491 healthy adult participants.

A total of 12 percent showed EIH following a time-restricted 5-kilometer run. This figure dropped to just 1.3 percent when participants completed the run without any time restriction, suggesting that blood in the urine occurred due to the intensity of the effort during the timed run.

The authors note that EIH usually resolves within 3 days and suggest seeing a doctor for any bleeding that lasts longer than 2 weeks.

4. Enlarged prostate

Benign prostatic hyperplasia (BPH) is the medical term for an enlarged prostate.

The prostate is a gland that makes up part of the male reproductive system and helps produce semen. It sits below the bladder and in front of the rectum.

An enlarged prostate can press down on the urethra, making urination difficult. The bladder may compensate by working harder to release urine, which could lead to damage and bleeding.

BPH affects around 50 percent of adult males aged 51–60 years and as many as 90 percent of those aged over 80 years.

Symptoms of BPH include:

  • an urgent need to urinate
  • frequent urination, especially at night
  • difficulty starting urination
  • needing to push or strain while urinating
  • a weak or intermittent urine flow
  • a feeling that the bladder is full even after urinating
  • blood in the urine

In severe cases, a person with BPH may be unable to urinate at all. This is a medical emergency requiring immediate attention.

5. Recent catheterization

Urinary catheter equipment in a surgery room.

A catheter can sometimes lead to a UTI, which can cause blood in the urine.

Some people may have difficulty passing urine due to an injury, surgery, or disease. A urinary catheter (UC) is a flexible tube that helps drain urine from the bladder.

In males, UCs can be indwelling or external. An indwelling catheter is inserted into the bladder via the urethra. It may remain in the bladder for several days or weeks.

An external catheter is a device that fits over the penis and collects urine into a drainage bag.

Both types of catheter can allow bacteria to enter the urethra and multiply, possibly leading to a catheter-associated urinary tract infection (CAUTI). This can result in blood in the urine.

According to the Centers for Disease Control and Prevention (CDC), 75 percent of UTIs acquired in hospitals result from catheter use.

The symptoms of a CAUTI are the same as those for general UTIs but may also include spasms in the lower back or abdomen.

6. Injury to the kidneys

Glomeruli are tiny structures within the kidneys that help filter and clean the blood. Glomerulonephritis (GN) is the term for a group of diseases that can injure these structures.

In people with GN, the injured kidneys are unable to remove waste and excess fluid from the body. Without treatment, GN can lead to kidney failure.

Chronic GN often occurs in young men who also have hearing and vision loss.

Acute GN comes on suddenly and may cause the following symptoms:

  • facial puffiness in the morning
  • blood in the urine
  • reduced urination
  • shortness of breath
  • coughing
  • high blood pressure

Chronic GN develops slowly. In some cases, people may not experience symptoms for several years. Signs and symptoms can include:

  • blood in the urine
  • protein in the urine
  • swelling of the face or ankles
  • frequent nighttime urination
  • bubbly or foamy urine

7. Medications

The following medications may cause hematuria:

  • Blood thinners: These drugs help prevent blood clots, but some types, including warfarin and aspirin, may cause blood in the urine.
  • Nonsteroidal anti-inflammatory drugs, or NSAIDs: If a person uses these for long periods, they can damage the kidneys and cause blood to appear in urine tests. However, they are unlikely to cause visible blood in the urine.
  • Cyclophosphamide and ifosfamide: These are chemotherapy drugs that can cause hemorrhagic cystitis, which is the sudden onset of blood in the urine and bladder pain and irritation.
  • Senna: Long-term use of this laxative can result in hematuria.

Anyone who suspects that blood in their urine results from medication use should speak with a doctor about changing to another medication or ways to relieve side effects.

8. Prostate cancer

Around one in 10 men in the United States will receive a diagnosis of prostate cancer in their lifetime.

With early diagnosis and treatment, prostate cancer is usually curable. However, few men will experience symptoms during the early stages of the disease, so it is vital to attend regular screening tests.

When symptoms of prostate cancer do occur, they may be similar to those of BPH.

Additional signs and symptoms of prostate cancer include:

  • dull pain in the lower pelvic area
  • pain in the lower back, hips, or upper thighs
  • painful ejaculation
  • blood in the semen
  • appetite loss
  • unexplained weight loss
  • bone pain

Men experiencing any of the symptoms of prostate cancer should visit a doctor as soon as possible.

9. Bladder cancer

Male feet standing on scales to check for weight loss alongside blood in the urine.

Unexplained weight loss alongside urine discoloration could indicate bladder cancer.

In the early stages of bladder cancer, people may experience very few symptoms. The earliest indication is usually blood in the urine.

Some people may notice urine discoloration. For others, the traces of blood are only detectable in a urine test.

Other possible symptoms of early-stage bladder cancer include:

  • a frequent or urgent need to urinate, especially at night
  • difficulty urinating
  • a weak urine stream
  • pain or burning during urination

Symptoms of more advanced bladder cancer include:

  • an inability to urinate
  • lower back pain on one side
  • swelling in the feet
  • a loss of appetite
  • unexplained weight loss
  • bone pain

Website: https://www.medicalnewstoday.com/articles/324824.php

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