What causes blood in urine?

Blood in urine, also known as hematuria, can be a concerning sign, particularly when it appears without an apparent cause. The presence of blood in urine can occur due to a variety of reasons, each with unique symptoms and potential complications.

In the urinary system, the kidneys filter blood and eliminate waste products through urine. This fluid then flows through the ureters to the bladder, where it is stored before being expelled through the urethra. When blood appears in the urine, it often indicates some issue within this system.

Several factors can lead to hematuria, including urinary tract infections (UTIs), kidney stones, kidney disease, or bladder or kidney cancer. For instance, UTIs, which are typically caused by bacteria, can irritate the lining of the urinary tract, resulting in bleeding. Similarly, kidney stones may cause bleeding when they block the urinary tract or are being passed through it.

What Is Blood in Urine (Hematuria)?

Blood in urine, known as hematuria, is the medical term for the presence of blood cells in urine (peeither grossly visible or microscopically present). It is a condition characterized by either visible redness or pinkness of the urine or detection under a microscope. Various underlying causes are possible, including kidney disorders, urinary tract infections, stones, or cancer, among others.

What causes hematuria or blood in urine?

Hematuria, or blood in urine, can be caused by various factors such as infections in or inflammation of the bladder, kidney, urethra, or prostate; trauma; and urinary tract stones or a recent urinary tract procedure. It may also occur due to vigorous exercise, kidney diseases, or certain medications.

The following are some possible causes of blood in urine (hematuria), including various kidney and urinary tract problems, bleeding disorders, and medication side effects. Seek immediate medical attention if accompanied by other symptoms and consult a healthcare provider for proper diagnosis and treatment.

Blood in urine (hematuria) may be caused by problems in the kidneys or urinary tract, including:

1. Cancer of the bladder or kidney
2. Infection of the bladder, kidney, prostate, or urethra
3. Inflammation of the bladder, urethra, prostate, or kidney (glomerulonephritis)
4. Injury to the bladder or kidney
5. Kidney or bladder stones
6. Kidney disease after strep throat (post-streptococcal glomerulonephritis)

In other cases, the blood may be coming from sources such as:

1. Bleeding disorders (such as hemophilia)
2. Blood clots in the kidneys
3. Blood-thinning medicines (such as aspirin or warfarin)
4. Sickle cell disease
5. Thrombocytopenia (low numbers of platelets)

Blood in urine should never be ignored. Seek immediate medical attention if accompanied by other symptoms like discomfort with urination, frequent urination, unexplained weight loss, urgent urination, fever, nausea, vomiting, shaking chills, or pain in the abdomen, side, or back.

Dr. Samarth Agarwal may conduct a physical exam, ask questions, and perform tests like urinalysis, urinary cytology, urine culture, 24-hour urine collection, kidney biopsy, and CT scan of the abdomen to determine the cause and appropriate treatment.

Blood in Urine Diagnosis and Tests

A urinalysis, specifically the blood in urine test, examines various aspects of urinary health, assessing the presence of blood cells and other substances.

Common symptoms, such as painful urination and abdominal pain, may trigger this test, while a clean catch method ensures an accurate sample. 

Diagnosis of Blood in Urine (Hematuria)

1. Urinalysis: A basic urine test to detect the presence of blood.
2. Dipstick test: A urine test strip that changes color when blood is present, though it may give false positives.
3. Microscopic examination: Examination of urine under a microscope to identify red blood cells.
4. Imaging tests: If a cause is not found, further tests like CT MRI scan, or ultrasound exam may be necessary.
5. Cystoscopy: An examination of the bladder and urethra using a thin, flexible tube with a camera.
6. Urine culture: To identify an infection causing the hematuria.
7. Blood tests: PT, PTT, or INR tests may be conducted to check for abnormal clotting.
8. Intravenous pyelogram (IVP): An X-ray of the kidneys, ureters, and bladder after injection of a contrast material.
9. Renal function tests: To evaluate kidney function, if necessary.
10. Genetic testing: To identify hereditary causes, such as Alport syndrome or IgA nephropathy.

Symptoms and Causes of Blood in Urine

1. Gross hematuria: Visible blood in urine.
2. Microscopic hematuria: The presence of blood in urine is only detected under a microscope.
3. Common causes include urinary tract infections, kidney stones, tumors, or inflammation.
4. Less common causes include glomerulonephritis, lupus, or bleeding disorders.
5. Certain medications, such as aspirin or cyclophosphamide, can cause hematuria.
6. Strenuous exercise or straining during bowel movements can sometimes cause temporary hematuria.
7. Dehydration may lead to concentrating urine and causing it to appear dark, potentially giving the appearance of blood in urine.

What is the most common reason blood in urine?

Urinary tract infections (UTIs), found in the bladder, ureters, or kidneys, are the most common cause of blood in urine. Common types include bladder infections (cystitis) and kidney infections (pyelonephritis).

What is the treatment for blood in your urine?

Treatment for blood in urine may involve taking antibiotic medicines to clear a urinary tract infection. For an enlarged prostate, urologists typically use two classes of medications. Other causes may require different treatments, as advised by healthcare providers. In case of suspected blockage due to blood clots, doctors often insert a flexible tube in the urinary tract.

Can lack of water cause blood in urine?

Lack of water does not typically cause blood in urine (hematuria) due to dehydration alone. However, severe or frequent dehydration may potentially contribute to hematuria in combination with other underlying conditions like urinary tract infections, bladder injuries, or kidney stones. Staying well-hydrated is beneficial for your urinary tract, and dark-colored urine indicates dehydration.

Is blood in urine serious?

Blood in urine (hematuria) is often harmless but can be a sign of a serious illness. When visible, it’s called gross hematuria, and when not, it’s called microscopic hematuria. In most cases, it’s caused by an infection, which can be easily treated. However, untreated hematuria could lead to bigger problems, especially if the cause is more serious. Seek medical advice to ensure proper diagnosis and treatment.

How much blood in urine is normal?

A normal range for red blood cells (RBC) in urine is up to four RBCs per high-power field. However, different laboratories may have different ranges for a “normal” result. Hematuria, or blood in urine, affects an estimated 2% to 30% of the U.S. adult population, with any blood in the urine considered abnormal.

Where does blood in urine come from?

Blood in urine (hematuria) can originate from any part of the urinary tract, such as the kidneys, ureters, bladder, or urethra. Causes may include infections, kidney disease, urinary tract stones, or certain cancers like bladder or kidney cancer. Exercise, unexplained individual variation, and urinary tract infections are also possible reasons for blood in urine. Consult your local medical authority for advic

What causes blood in urine after dialysis?

Blood in urine after dialysis is often caused by renal cell carcinoma, angiomyolipoma, vascular diseases such as polyarteritis nodosa (PAN), or spontaneous hematomas, especially in those with acquired renal cystic disease (ARCD). Less commonly, kidney or bladder cancer, irritation or swelling in the urinary system, or medication side effects like rifampin, warfarin, and chloroquine could be the culprit. Always consult a healthcare professional for a definitive diagnosis.

Which STI causes blood in urine?

Chlamydia and gonorrhea are the STIs that most commonly cause blood in urine. These infections can result in a swelling of the urethra in men, leading to blood in the urine, and may also affect women, potentially leading to endometriosis. Babies born to infected mothers can also get lung and eye infections.