Blood in urine is also referred to as hematuria and can be of 2 types. Gross hematuria is when the blood in urine is visible to the naked eyes producing pink, red or brown colored urine. Microscopic hematuria on the other hand is when the blood in urine can only be seen with the help of a microscope.

Blood fines itself in urine when it leaks from the kidney or other body parts. This may be caused by an underlying medical condition such as an infection, cancer, kidney disease, sickle cell anemia or an injury. But in some cases, the cause is not associated with any underlying medical condition and may simply be the result of stress or use of certain drugs.

While the presence of blood in urine is usually not a call for alarm, in some cases it could indicate a life threatening condition such as cancer. It is therefore important to determine the cause and hence seek appropriate treatment.

Who is at risk of having hematuria?

Although everyone can have hematuria or blood in urine, there are certain things which make some people more likely than others. This includes:

  • Age
  • Smoking
  • Family history of kidney stones or kidney diseases
  • Presence of an enlarged prostate (in men)
  • Participation in strenuous exercises
  • Taking certain medications such as pain killers or antibiotics
  • Have recently had an infection or currently having one.
  • Exposure to radiation or chemicals

Note however that being guilty of any of the above does not necessarily mean you will have blood in urine.

Causes of blood in urine

Here are the factors than cause blood in urine:

Kidney Disease

The kidney plays an important role in getting rid of waste in your blood, regulating blood pressure, maintaining water and mineral balance in your blood, helping in the production of red blood cells and vitamin D.  A kidney disease occurs when your kidney stops working suddenly (referred to as acute renal failure) or when it does not function properly for more than 3 months (referred to as chronic kidney disease). Several factors can cause a kidney disease including: diabetes, high blood pressure, problem with the immune system, injury to the kidney, enlarged prostate (in men), inflammation of the kidney filtration system (glomerulonephritis), viral or streptococcus infections.

Polycystic kidney disease (PKD) is an inherited form of kidney disease whereby cluster of cysts grow inside your kidney causing it to be larger. This eventually damages the kidney.

Bacteria or Virus Infection

This is one of the most common causes of blood in urine. Such infections occur in the urinary tract, bladder or kidney. Symptoms usually include very strong smelling urine, constant urge to urinate, pain and burning sensation when urinating.

Cancer of the Kidney, Bladder or Prostate

Cancer of the kidney, bladder or prostate does not produce any physical symptoms as they grow.  Unfortunately, once symptoms become noticeable, then it might be too late for any cure. Therefore seek medical attention once you notice any blood in your urine. Cancer can be cured when detected early enough.

Kidney Injury

An accident or a fight can cause injury to the kidneys. This may result to visible blood being observed in urine.

Enlarged Prostate

The prostate is a walnut-sized gland located inside the male body underneath the bladder and envelops the urethra. As men approach their middle age, the prostate may enlarge up to the point whereby it compresses the urethra and thus partially block the flow of urine. This causes difficulties urinating and the inability of the bladder to be completely empty and puts the owner at risk of developing a urinary tract infection. An enlarged prostate may also be referred to as benign prostatic hyperplasia (BPH).

Inherited disorders

Sickle cell anemia is an inherited disorder which affects the hemoglobin in red blood cells. This causes the red blood cells to adopt a sickle shape. Such unhealthy red blood cells breakdown or die very early. Sickle cell anemia can cause both gross and microscopic hematuria.

Other inherited disorders causing blood in urine include hemophilia in which blood does not clot normally and alport syndrome, which affects collagen production causing a progressive loss in kidney function.


Some drugs are common candidates for blood in urine. Examples include the pain killer aspirin, blood thinners such as heparin and warfarin, anticancer drugs such cyclophosphamide and antibiotics such as aspirin.

Strenuous Exercise

 The cause of blood in urine as a result of difficult exercise is not well understood. However, it may be related to increased breakdown of red blood cells, trauma to the bladder or dehydration. Strenuous or difficult exercise hardly leads to gross hematuria. So if you see visible blood in your urine after a strenuous exercise, then don’t assume it’s due to the exercise. Rather see a doctor.

Kidney or bladder stones

Minerals and salts in concentrated urine may be able to stick to each other and form crystals which become deposited on the walls of the kidney or bladder. With time, the crystals may develop into small hard stones which can then become even much larger by the day.

Small kidney stones are generally not painful and will easily be passed out with urine. But larger stones can cause severe symptoms due to blockage. Symptoms include pain on the side of the tummy, pain when urinating, nausea and vomiting and gross or microscopic hematuria.


During menstruation or immediately after menstruation, one may observe blood in urine. This is not a call for concern.

Sexual Activity

Rough or dry intercourse can cause bruises which will cause blood to leak during urination.

Symptoms of blood in urine

Microscopic hematuria produces no visible signs or symptoms. Gross hematuria however, will cause your urine to be pink, red or brown.

Apart from changes in urine color, pain during urination may also be an indication of blood in urine even if you cannot see it with your naked eyes.

How to diagnose the cause of blood in urine?

To determine the cause of blood in urine, your doctor may first ask you for any of the following: Your health history including infection, kidney stones, kidney disease or injury; family health history; menstruation; smoking habit etc.

He can then order for your urine sample. The urine sample will be used to test for any sign of infection or disease. Depending on the outcome of the urine test, your doctor may request a repeat of the urine test in order to make sure the first test was correctly performed.

He may also carry out some physical examination to check for any pain or tenderness in the bladder or kidney area. The prostate examination (in men) will also be conducted using a digital rectal exam. A pelvic exam however will be conducted for women.

Other examinations or tests include:

  • Blood Test: Use to measure the levels of the protein creatinine. High levels of creatinine is an indication of kidney disease.
  • Cystoscopy: Cystocopy is an examination used to view the inside of the bladder or urethra. It is used to detect any sign of cancer, infection or other conditions
  • Kidney Imaging Tests: Such imaging tests include ultrasound, Computer Tomography (CT) scan and Magnetic Resonance Imaging (MRI). Your doctor will determine which of these tests is best for you. Such imaging test can be used to check for cancer cells, kidney or bladder stones and other problems.

In some instances, the doctor might not be able to determine the cause of the blood in urine. He/she may then reschedule for new tests or examinations after one year or after several years.

Treatment of blood in urine

The first step in treating hematuria is to diagnose its cause. Once the cause is determined, then treatment will simply be based on treating the underlying conditions.

Blood in urine due to a bacterial infection is treated using antibiotics. If it’s a viral infection then an antiviral will be used.

For enlarge prostate, treatment involves surgery or prescribed medications such as alpha blockers or 5-alpha reductase inhibitors.

Treatment of kidney or bladder stones involves breaking the stones into tiny pieces so that they can easily be passed out in urine. This can be achieved with prescription medications and treatment plan. Additionally, a procedure called extracorporeal shock wave lithotripsy (ESWL) can be employed to break the stones into smaller pieces. Alternatively, your doctor may use a scope (a flexible telescope) together with other tools to find, remove or break stones. Surgery may also be carried out in the treatment of kidney stones.

Blood in urine caused by medications, food or strenuous exercise usually disappear after some few days

For treatment of kidney or bladder cancer, you will be referred to an oncologist or urologic surgeon. Treatment options include surgery, chemotherapy or radiotherapy.


How to prevent blood in urine

Here is how you can avoid having blood in urine:

  • Drink at least 1.5 L of water per day.
  • Practice good hygiene
  • Practice safe sex and urinate immediately after intercourse
  • Avoid exposure to chemicals or radiation
  • Avoid smoking