When you experience hematuria, red blood cells leak from your kidneys or your urinary tract into your urine. Blood in your urine is not always a sign of a serious medical condition, but it should be taken as a warning that something could be wrong. Hematuria can be a sign of many medical conditions:
- Bladder or kidney stones
- Kidney disease
- Kidney injury
- Enlarged prostate
- Urinary tract infection
- Blood clots
- Kidney infections
- Cancer of kidneys, bladder, or urethra
- Sickle cell anemia
If you notice blood at the following points during urination, it can have different implications:
- Blood at the beginning of urination may mean the bleeding originates in the urethra.
- Blood in the urine stream may be due to your bladder, kidneys, or ureters.
- Blood at the end of urination may suggest that the cause involves the bladder or prostate.
If you’re over age 35 and are a smoker, blood in your urine may be a sign of bladder cancer.
Certain medications can also cause urinary bleeding:
- cyclophosphamide (Cytoxan)
- penicillin
- aspirin
- heparin
- anticoagulants such as warfarin (Coumadin), rivaroxaban (Xarelto), dabigatran (Pradaxa), or apixaban (Eliquis)
Extremely strenuous exercise can also cause hematuria, possibly because it can lead to bladder trauma, dehydration, or the breakdown of red blood cells. If you’re a runner or have exercised strenuously and notice blood in your urine, contact your doctor.
Blood may also come from these other sources:
- The vagina during menstruation
- Ejaculation in men (often because of a prostate problem)
- A bowel movement due to hemorrhoids or other issues
What Causes Small Blood Clots in Urine?
Urinary tract infections, kidney stones, and prostate problems are common causes of small blood clots, which can sometimes look like coffee grounds. If you notice blood clots in your urine — even small ones — you should contact your doctor. Larger blood clots can block the flow of urine and cause discomfort, and they’re often a sign of a medical emergency.
If you notice different shapes of blood clots in your urine, such as a wormlike appearance, it may be a sign that you are bleeding from the urethra or prostate. Painful clots may come from the tubes that connect your kidneys to your bladder, known as ureters.
Can Dehydration Cause Blood in Urine?
While dehydration is less likely to be a direct cause of hematuria, it can lead to related conditions.
For example, low urine volume due to consistent dehydration can lead to kidney stones that can cause blood in the urine. Dehydration may also contribute to blood in the urine during extreme exercise.
Causes of Hematuria in Children
Visible and microscopic blood in children’s urine can indicate a medical condition or a risk of developing one.
If red, pink, or brown discoloration is visible, the change is likely due to medication or certain foods. Regardless, parents should consult a doctor if they notice any abnormal color changes in their child’s urine.
Roughly 4 percent of children will experience microscopic blood in their urine, according to a paper from 2020. Because microscopic blood isn’t visible, parents should also look for these symptoms of possible conditions that might be causing it:
- Urinating more often than usual
- Painful urination
- Fever
- Abdominal pain or masses
- Pain in the sides
- Cola-colored urine
- High blood pressure
- Swelling
- Hearing loss
- Eye abnormalities
- Skin rashes
- Joint inflammation
- Fatigue
- Easy bruising
- Hemarthrosis
- Bleeding gums
- Bleeding joints, causing pain, reduced movement, warmth, and swelling
Hematuria in children can be a sign of the following:
- Polycystic kidney disease
- Kidney stones
- Hereditary nephritis
- Alport syndrome
- Sickle cell disease
- Kidney cysts
It’s also possible that your child has thin basement membrane disease. In many children, no symptoms other than blood in the urine are present. However, in some children, high blood pressure, swelling, and reduced urine output might occur.