Blood in the urine

Bloody urine, also called hematuria is defined as the presence of blood in the urine. It can be microscopic and only be detected on urine analysis (microscopic hematuria). When visible with the naked eye, bloody urine can be pink, red, or brown (gross hematuria).

In some cases, particularly in women, the blood coming from rectal or vaginal bleeding can mix up with urine (false hematuria). Occasionally, false hematuria can result from the reddish coloring given to the urine by some foods (beetroot). Some drugs such as rifampicin and phenytoin can also discolor urine and give an impression of gross hematuria

Strenuous exercise can also cause blood to show up in the urine. 

Seeing blood in our urine makes us scarred. Sometimes, it can go away on its own. Empiric treatments, like antibiotics of homemade remedies, can only casually be effective. However, ignoring an episode of hematuria is not a good idea. It can lead to the worsening of serious conditions like cancer or kidney disease. It is better to talk to the doctor as soon as possible who will be able to determine the reason for the bleeding.

What causes hematuria?

Hematuria happens when leakage of blood arises from any part of the urinary tract, from kidneys to the urethra. There are many possible causes of hematuria:

Infection

Infection is one of the most common causes of hematuria. The bacteria can enter the urinary tract through the urethra that is the tube that carries urine out of the bladder (causing urethritis). The infection can move up into the bladder or into the prostate causing cystitis or prostatitis, or up to the kidney causing pyelonephritis. Any of these infections can be the source of the blood leakage and the hematuria comes with symptoms of infection like painful urination, frequent urination, perineal of flank pain.

Stones

With kidney and ureteral stones, the urine is usually dark red or brown. Hematuria can be accompanied by a particular kind of pain called renal colic when the stone is obstructing. With bladder stones, the hematuria is associated with painful urination, frequent urination, or urgent urination. 

Enlarged prostate

After the 50s, a possible cause of hematuria is an enlarged prostate. This gland is just beneath the bladder and near the urethra. The prostate enlargement can compress the blood vessels in the bladder neck causing varicosities that can leak. Also, infections are a common reason for bleeding in enlarged prostate patients. Hematuria in enlarged prostate patients is usually associated with frequent urination and nocturia.

Kidney disease

A less common reason for seeing blood in the urine is kidney disease. A diseased or inflamed kidney can cause hematuria. This disease can occur on its own or as part of another disease, such as diabetes.

In children ages 6 to 10 years, kidney disorder post-streptococcal glomerulonephritis may cause hematuria. This disorder can develop one to two weeks after an untreated strep infection. Once common, it's rare today because antibiotics can quickly treat strep infections.

Cancer

Often, the first symptom of bladder cancer is blood in the urine without any other symptom. Renal and prostate cancers usually bleed only in advanced stages.

Medications

Certain medications can cause hematuria. These include:

  • penicillin
  • aspirin
  • blood thinners like heparin and warfarin (Coumadin)
  • cyclophosphamide, which is a drug used to treat certain types of cancer

Less common causes

There are a few other causes of hematuria that aren't very common. Rare blood disorders such as sickle cell anemia, Alport syndrome, and hemophilia can cause blood in the urine.

When to see a doctor

In all cases of blood in the urine, to see a doctor is a good idea. Hematuria as a single sign, without any other symptom, might be caused by cancer.

Q&A section

Q:  what causes bloody urine in females?

A: the leading cause of bloody urine in females is urinary tract infection (UTI). In these cases, hematuria is usually accompanied by painful urination.

Q: what causes bloody urine in males?

A: the leading cause of bloody urine in males is the stone disease. In these cases, hematuria is usually accompanied by renal colic and sometimes painful urination.  

Q: will blood in the urine go away on its own?

A: yes. However, in all cases of hematuria must be evaluated by a doctor.

Q: why blood in the urine during pregnancy?

A: pregnancy is not a particular risk for hematuria; however urinary tract infections (UTI) are more common and can be accompanied by hematuria.

Q: is bloody urine a sign of pregnancy?

A: while in late pregnancy hematuria might commonly due to urinary tract infection, bloody urine is not a specific sign of it.