The Causes of Blood in Your Urine

Discovering blood in your urine, also known as hematuria, can be very unsettling. It may be the result of an abnormality within the urinary tract.  Blood in the urine can be a red flag for an internal problem. Therefore, anytime you see blood in the urine, it should get you to seek medical attention.

Any blood found in the urine is most likely linked to the urinary tract. The urinary tract is the system comprised of the kidneys, the ureters (thin tubes that carry urine from the kidneys to the bladder), the bladder (which holds urine), and the urethra (the tube that carries urine from the bladder out of the body).

Appearance of Urine

The color and intensity of blood in the urine change the appearance. Bright red blood or pink urine can mean arterial blood, whereas dark red blood can indicate venous blood. Dark red or brown urine can indicate a rare condition called rhabdomyolysis (a breakdown of muscle cells) or hemoglobinuria (destruction of red blood cells that are removed from the body in the urine).

It's important to note that discoloration is not always due to blood. Eating certain foods, like beets or rhubarb, can give urine a pinkish to red color. Some supplements and medications have the same effect.

On the other hand, if your urine has a deep brown hue (also referred to as being "cola-colored"), it may indicate an acute liver problem, such as hepatitis.

Symptoms

Hematuria can be classified as macrohematuria or microhematuria. Blood that you can see in your urine is called macrohematuria, or gross hematuria. Mircrohematuria, on the other hand, refers to blood cells that can only be seen under a microscope.

Individual symptoms from hematuria will vary based on the cause. Microhematuria can be asymptomatic, meaning no symptoms are present. It will be important to tell your healthcare provider any symptoms you are experiencing or provide a recent history of events to assist with diagnosing the cause.

Causes

Hematuria is a common symptom occurring in roughly a third of all people during their lifetime. A single episode may be related to a mild condition such as trauma, whereas persistent or recurrent hematuria is suggestive of a more serious medical condition.

Among the possible causes:

• Kidney stones are often large and jagged and can cause damage as they travel through the ureters, bladder, or urethra.
• Urinary tract infections (UTIs) commonly cause hematuria and can develop anywhere from the kidneys to the urethra. Bleeding is typically the result of a long-standing, untreated infection. In addition to discoloration, the urine may be foul-smelling.
• Kidney diseases, both acute and chronic, can result in urinary bleeding. People with diabetes are particularly prone to developing kidney problems.
• Benign prostatic hyperplasia (enlarged prostate) can also be the cause of blood in the urine, especially in men over 50. The urine goes through the prostate as it exits the urethra. If the prostate is large it can bleed and cause micro or gross hematuria. Frequency, urgency, hesitancy, and urinating at night are common side effects of benign prostatic hyperplasia.
• Sexually transmitted infections associated with the irritation of the urethra or bladder can cause hematuria.
• Menstruation can make it seem like blood is in the urine as it exits the body and mixes with the urine.
• Sexual activity can also cause blood in the urine.
• Vigorous exercise is a fairly common cause of microscopic hematuria. Its presence in military recruits earned it the title "march hematuria."

It is important to remember that hematuria is a symptom and not a disease. As such, it is not treated symptomatically. Rather, treatment is focused on resolving the underlying condition that is causing the hematuria, whatever it may be. Once that is successfully treated, the bleeding will usually stop.

More Serious Causes

In more rare cases, hematuria can be caused by a serious concern such as:

• Bladder and kidney cancer are less likely causes of hematuria, but bleeding is common with the formation of a malignant tumor. 
• Prostate cancer can also cause bleeding in the adjacent urinary tract.
• Polycystic kidney disease can cause blood in the urine as the cysts take over the kidneys.
• Inflammation of the kidneys, urethra, bladder, or prostate.
  
• Injury to any part of the urinary tract can result in blood in the urine. Sports trauma and auto accidents are common sources of these injuries.

What Medications Can Cause Hematuria

Some medications used to treat other conditions can cause hematuria:

• Cytoxan
• Medications that thin the blood (such as aspirin, heparin, warfarin)
• Penicillins
• Sulfa-containing drugs (Bactrim)

What Are the Tests for Hematuria?

If you have blood in the urine, your healthcare provider will typically ask you for a urine sample. A full urinalysis will not only look out for red blood cells but protein, glucose, or any signs of infection. The presence of excess protein (proteinuria) is particularly helpful as it may point your healthcare provider in the direction of kidney impairment.

Your healthcare provider may order additional tests to pinpoint the exact cause of bleeding:

• Blood tests may be used to evaluate creatinine (CR) and blood urea nitrogen (BUN), among other things
• Imaging tests, such as an ultrasound, computerized tomography (CT) scan, or magnetic imaging resonance (MRI)
• Cystoscopy may be used to visually examine the bladder using a flexible catheter equipped with a camera that is inserted through the urethra
• A biopsy may be required to evaluate any suspicious findings in your kidneys or bladder

Summary

Blood in the urine is a symptom of something else happening in the body that is affecting the urinary tract. It takes investigation with your healthcare provider to figure out the cause. There are many reasons why there could be blood in your urine, such as an infection or inflammation.

A Word From Verywell

If you notice blood in your urine, make an appointment with your healthcare provider to have the necessary tests performed. There may be many different reasons for blood in your urine, so don't assume the worst. Many causes are easily treated. 

If your primary care healthcare provider thinks the problem is due to a chronic condition, they may refer you to a specialist, such as a urologist, for further investigation.

However, if bleeding and pain accompany hematuria, it's important to seek medical care as soon as possible. In the end, it may only be a simple infection, but it could also be an indication of a more serious illness requiring emergency intervention.