15 Causes of Blood in Your Urine

2. Kidney Disease

Kidney disease can cause blood in your urine when the tiny filters in your kidneys, called nephrons, become damaged or inflamed. This damage allows red blood cells to leak into your urine, which may cause it to appear pink, red, or brown. Sometimes, the amount of blood is so small it can only be seen under a microscope.

Common causes of kidney disease include infections, high blood pressure, and diabetes. These conditions can gradually weaken kidney function over time. Genetic conditions such as polycystic kidney disease may also cause bleeding if cysts rupture or press on nearby tissues.

Symptoms that may accompany blood in the urine include swelling around the eyes or ankles, fatigue, and changes in urination patterns. Pain in the lower back or sides may suggest additional issues such as kidney stones or infection.

3. Enlarged Prostate

An enlarged prostate, also called benign prostatic hyperplasia, often causes blood in urine for men over 50. As it grows with age, it can press on your urethra, the tube that carries urine out of your body.

This pressure can make it harder for urine to flow. You might notice a weak stream, difficulty starting to urinate, or the need to go more often, especially at night. Sometimes, this strain can irritate the bladder or nearby blood vessels, which may cause small amounts of blood in your urine.

Doctors may use urine tests, a digital rectal exam, ultrasound, or a prostate-specific antigen (PSA) blood test to check for prostate problems. These help rule out other causes such as infection or cancer.

For mild cases, lifestyle changes and regular checkups may be enough. When symptoms worsen, your doctor may suggest medicines that relax the bladder neck and prostate muscles or shrink the gland. In more serious cases, surgery or a less-invasive procedure may relieve symptoms by removing or reducing prostate tissue.

4. Prostate Infection

Bacteria can infect the prostate gland, causing a prostate infection or prostatitis. This small gland sits below your bladder and helps produce semen. When inflamed or infected, it can affect how you urinate and cause pain or discomfort.

You might notice burning or stinging when you urinate, a strong urge to go frequently, or pain in your lower abdomen, back, or between your legs. Some people also see blood in their urine or semen. In some cases, you may feel feverish or have chills.

Doctors diagnose a prostate infection by checking your urine or blood for signs of infection. They may do an ultrasound or other imaging tests to check for swelling or blockage. Prostate massage is generally avoided during testing, as it can worsen the infection or increase discomfort.

Treatment typically involves antibiotics or medications that relieve pain and swelling. It is important to complete the full course of medication even if you start feeling better. Drinking plenty of water and resting may help your body recover more quickly.

5. Bladder Stones

Minerals in your urine can build up and harden inside the bladder to form bladder stones. This happens if the bladder doesn’t empty fully when you urinate. When urine stays too long in the bladder, minerals can clump together and form stones.

The stones can rub against the bladder walls and cause irritation. This may lead to visible or microscopic blood in your urine. You might also notice pain in your lower belly or burning when you urinate. Some people feel the urge to urinate often but pass only small amounts each time.

Common causes include an enlarged prostate, bladder infections, or problems with bladder emptying. Dehydration may increase the risk because concentrated urine allows minerals to crystallize more easily. Doctors usually confirm bladder stones through imaging tests like an ultrasound or a CT scan.

6. Kidney Injury

If you have a kidney injury, your kidneys have been damaged and may not filter your blood as well as they should. When blood appears in your urine due to this damage, it may look pink, red, or brown. Kidney injury can happen suddenly after an accident or develop gradually due to another illness or condition.

Kidney injury can result from traumatic injuries, such as a car accident, fall, or contact sports. Even a small blow to your back or side can bruise kidney tissue. Sometimes, medical treatments or surgeries that affect blood flow to your kidneys may also cause injury.

Certain health problems can increase your risk of kidney injury. Severe infections, dehydration, or very low blood pressure can reduce blood flow to your kidneys. Using some medications that affect kidney function, including certain pain relievers or diuretics, can also raise the risk.

Signs that your kidneys might be injured include pain in your lower back, swelling in your hands or feet, and changes in how often you urinate. Blood in your urine is an important warning sign.

7. Bladder Injury

A bladder injury can cause blood to appear in your urine. External force, such as a car crash, sports accident, or fall, can damage the bladder. Sometimes pelvic fractures can pierce the bladder wall and lead to bleeding.

You might notice pain in your lower abdomen, difficulty urinating, or bruising around your pelvis. In some cases, urine may leak inside the body, which can cause infection or swelling. When the bladder is full during trauma, the risk of rupture increases because it is stretched and more likely to tear.

Doctors usually confirm this injury with imaging tests like CT scans or specialized X-rays using dye. Before placing a catheter, they check the urethra to make sure it isn’t torn. Once confirmed, treatment focuses on draining urine, repairing the bladder, and preventing infection.

Mild injuries may heal with catheter drainage. More serious cases often need surgery to close tears and remove any leaked urine. Hospital monitoring and fluids may be necessary if there are signs of bleeding or low blood pressure.

8. Strenuous Exercise

You might notice blood in your urine after intense physical activity. Long or high-impact exercise can cause your red blood cells to break down or your bladder wall to become irritated. This is more common after endurance activities such as running, cycling, or heavy weightlifting.

During exercise, your kidneys and bladder experience more stress because blood flow shifts to your muscles. Small amounts of blood can leak into your urine, making it appear pink, red, or cola-colored. This is often called exercise-induced hematuria and usually goes away within a few days once you rest and drink plenty of fluids.

If blood remains in your urine after several days or if you also notice pain or fatigue, it is advisable to consult a healthcare provider. In rare situations, intense exercise can cause rhabdomyolysis, in which muscle tissue breaks down and releases proteins into the blood that can harm your kidneys.

9. Sickle Cell Anemia

Sickle cell anemia is an inherited blood disorder that changes the shape of your red blood cells. Instead of being round, the cells become curved or “sickle” shaped. When these misshapen cells clump together, they can block blood flow. This can lead to pain and organ complications.

When blood flow slows down, the kidneys can be affected. This sometimes causes blood to appear in your urine. The bleeding may come from small blood vessels in the kidneys that are damaged because of reduced oxygen and cell blockage. You might notice pink, red, or brown urine, or your doctor may find blood through a urine test.

Other signs of sickle cell anemia can include tiredness, shortness of breath, and frequent infections. Dehydration, stress, or illnesses may trigger symptoms by making the red blood cells stickier. Treatments vary depending on severity and may involve blood transfusions, supportive therapies, or medications that help the body make more flexible red blood cells.

10. Alport Syndrome

Alport syndrome is a rare inherited condition that affects your kidneys, hearing, and eyes. Changes in certain genes disrupt the production of collagen IV, a protein that maintains the normal structure of tiny filters in your kidneys. When these filters do not work properly, blood and protein can leak into your urine, which may look pink, red, or brown. Over time, kidney function may gradually decline.

Hearing loss often develops during late childhood or teenage years, and you might first struggle to hear higher-pitched sounds. Eye changes can also occur, such as altered lens shape or changes in retinal color, though they rarely cause vision loss.

Alport syndrome passes through families in different ways. The most common type affects the X chromosome, so males usually experience more serious kidney problems than females. Other forms result from changes in different genes and can affect both men and women equally.

11. It’s Not Blood…

Sometimes what looks like blood in your urine is not blood at all. Certain foods, drinks, or medicines can make your urine change color. This is often harmless and usually temporary. Beets, blackberries, and rhubarb can turn urine pink or red after you eat them. Some vitamins and food dyes can also give your urine unusual shades of red or orange.

If you recently started a new medicine, that might be the reason for the color change. Some antibiotics, blood thinners, and muscle relaxers can cause red or brown urine as a side effect. Usually, the color will go back to normal once you stop taking the medicine. But it’s a good idea to talk about any changes with your doctor before making any adjustments to your meds.

Bleeding from another source can also be mistaken for blood in urine. For example, menstruation or bleeding from hemorrhoids might mix with urine and appear as blood.

12. Trauma

Trauma can cause blood to appear in your urine when the bladder, kidneys, or urethra are injured. This may happen after a fall, car accident, sports injury, or blow to the lower abdomen. Even a hard impact when your bladder is full can lead to bleeding because the pressure inside the organ rises sharply.

Sometimes the bleeding is visible, but it can also be microscopic and only found through a urine test. You might also feel pain in the lower stomach or pelvis, have difficulty urinating, or notice swelling or bruising. These signs suggest that prompt medical evaluation is important, especially after a serious injury.

Health care providers use imaging tests, such as X-rays, CT scans, or ultrasounds, to find out how badly the urinary tract was damaged. In some cases, a thin tube drains urine while the bladder or urethra heals. If the injury is severe, surgeons may repair the tissues to prevent infection or urine leakage.

13. Hemophilia

Hemophilia can cause blood in your urine when bleeding happens inside your urinary tract. This blood disorder affects how your blood clots, so even minor injuries can lead to longer bleeding times. The blood you see in your urine usually appears red or brown and can vary with the severity of your condition.

You inherit hemophilia when the gene that controls clotting factors changes. These factors help your blood form clots to stop bleeding after an injury. If you have hemophilia A, your body has low levels of factor VIII. With hemophilia B, your body lacks enough factor IX. Both types increase the risk of internal bleeding, including bleeding into the kidneys or bladder.

Common signs include frequent joint pain, unexplained bruising, or bleeding that takes longer to stop. Bleeding inside your body can reach your urinary system and cause blood to appear in your urine.

14. Menstrual Bleeding

Menstrual bleeding is the monthly shedding of the uterine lining and usually lasts between three and seven days. Sometimes, blood may mix with your urine, and it can be difficult to tell whether the bleeding comes from your period or from your bladder or kidneys.

One way to help determine the source is to place a tampon in the vagina after urinating and observe whether it absorbs blood. If the tampon absorbs blood, the bleeding is likely menstrual. If the tampon remains clean, the blood may come from your urine or rectum.

Menstrual bleeding can vary in amount and color. Some people pass small clots, while others experience heavier flow with larger clots. Heavy bleeding that soaks through pads or tampons quickly, or bleeding that lasts longer than a week, may require medical evaluation.

Common causes of heavier menstrual bleeding include hormonal changes, fibroids, polyps, or bleeding disorders. Tests such as blood counts or imaging may be used to rule out other conditions.

15. Cancer

Blood in your urine, called hematuria, can signal cancer in the urinary system, such as the bladder, kidneys, or prostate. Tumors in these areas may cause bleeding by growing into the lining of the urinary tract or nearby tissues. Recognizing this symptom early can help with diagnosis and treatment.

In bladder cancer, blood in the urine may appear early and can come and go. You might not feel pain at first, but some people notice changes in how often or urgently they need to urinate. Kidney cancer can also cause blood to mix with urine, usually without other symptoms in the early stages.

Prostate cancer, which is more common in men as they age, may cause blood in the urine if the tumor affects nearby structures. In any of these cases, the bleeding may be visible, but sometimes the amount is small and only detected through a urine test.