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Blood in Urine? Here’s What It Could Mean

cartoon urine drops on left and right side with a cartoon blood droplet in the middle

If you’ve noticed blood in your urine, you’re probably worried about what it means. The medical term for this is hematuria. Blood in the urine can be from something harmless, like eating certain foods, but blood in your urine can also indicate something more far more serious, such as a urinary tract infection, kidney stones, kidney cancer, or bladder cancer. That’s why it’s important to have it evaluated by a healthcare provider. Your primary care physician may refer you to a specialist in digestive and kidney diseases, depending on your other symptoms. The treatment for blood in urine depends on the cause. Please continue reading to find out more. 

What is gross hematuria and microscopic hematuria?

If you can see blood in your urine with the naked eye, it is called gross hematuria. Bloody urine can appear pink, red, brown, or cola-colored. Even a little bit of blood in the urine can easily cause a change in color. The bloody urine may not be accompanied by painful urination or any other signs and symptoms. If you are passing blood clots in your urine, however, it can cause a burning pain.

If the blood in urine is only visible under a microscope when your doctor orders a urine test, it is called microscopic hematuria. 

In either case, you should not ignore blood in your urine. It's important to find out what is causing the bleeding in your urinary tract.

What does blood in the urine usually indicate?

Blood in your urine usually occurs due to a problem with some part of your urinary system, such as your kidneys, ureters, urinary bladder, or urethra. Some of the medical problems that can cause hematuria are briefly described below.

Urinary tract infections

UTIs are the most common cause of blood in the urine. Other symptoms of UTIs include frequency, urgency, pain, burning, and foul-smelling urine. If bacteria enter the kidneys, it is called a kidney infection or pyelonephritis, and this can cause fever and flank pain in addition. Bladder infections can cause blood in your urine, frequency, urgency, and a pressure or cramping sensation in the lower abdomen.

Bladder stones and kidney stones

Stones can cause excruciating pain and blood in the urine when they are being passed or if they become stuck in the ureter (the thin tube that carries urine from the kidney to the bladder).

Enlarged prostate gland in men

An enlarged prostate is common in middle-aged men. It can be a benign (non-cancerous) enlargement or prostate cancer. An enlarged prostate gland compresses the urethra, blocking the flow of urine. This can lead to signs and symptoms like blood in the urine, an urgent or persistent need to urinate, and difficulty urinating.

Kidney disease

Inflammation of the glomeruli (filtering systems) in the kidneys causes a kidney disease called glomerulonephritis. This can occur in people with diabetes or due to viral or strep infections, immune problems, or blood vessel disorders. Glomerulonephritis can cause microscopic hematuria, i.e., blood in the urine found by only a lab test. 


A kidney injury during a motor vehicle accident or contact sports can lead to gross hematuria (visible blood in your urine).


Blood in a urine sample can be a sign of advanced prostate, kidney, or bladder cancer. Unfortunately, red blood cells in urine are not present in the early stages, when cancers are more easily treatable. 

Blood disorders

Certain inherited conditions like sickle cell anemia and Alport syndrome are risk factors for blood in the urinary system.

Medication side effects

The antibiotic penicillin and the anti-cancer drug cyclophosphamide can cause leakage of blood cells into urine. Visible blood in the urine can also occur in people taking blood thinners or anticoagulants like aspirin, warfarin, and heparin

Strenuous physical activity

Rarely, strenuous exercise can cause gross hematuria (visible blood in your urine). The reason is unclear, but it is more common in runners and may be linked to trauma to the urinary system. If you develop blood in urine after an intense workout, don’t assume it is hematuria caused by exercise. See your doctor to rule out any health problems related to the urinary system.

What would cause blood in urine but no infection?

Bloody urine is often due to bacteria causing a urinary tract infection. But if there is no infection, there can be other causes, such as:

  • Men can develop hematuria in middle age (after age 50) due to an enlarged prostate. 
  • People with a personal or family history of kidney stones, kidney disease, or bleeding disorders are more prone to urinary bleeding. 
  • Taking certain medications like nonsteroidal anti-inflammatory drugs (aspirin and OTC pain relievers) and penicillin can cause red blood cells to leak into urine.
  • Very rarely, high blood pressure can cause urinary bleeding.
  • Long-distance runners may experience blood in urine. This is sometimes called jogger's hematuria but can occur after any type of strenuous physical activity.
  • Exposure to certain industrial chemicals may cause hematuria. 

How do you know if blood in urine is serious?

You cannot know if blood in your urine is serious. You should always seek medical attention if you notice blood in your urine or red-colored urine. 

People of all ages, including children and teenagers, can develop blood in urine. Something harmless and temporary could have turned your urine red, such as a medication (for example, the laxative Ex-Lax) or eating certain foods like rhubarb, beetroot, and berries. This red colored urine will go away on its own in a few days. 

But you may not be able to tell the difference between red-colored urine from food and blood in your urine. That’s why it’s best to see your healthcare provider if you notice urinary bleeding. 

Your doctor will obtain a medical history and perform a physical examination. The physical exam may include a digital rectal exam to check the size of the prostate. They may also order urine tests and lab tests. Depending on the results, more tests may be necessary, including blood tests and imaging tests. This will help to diagnose or rule out any serious problems that could be causing blood in your urine. 


  1. https://www.mayoclinic.org/diseases-conditions/blood-in-urine/symptoms-causes/syc-20353432
  2. https://pubmed.ncbi.nlm.nih.gov/9604474/