Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Hematuria, or blood in the urine, can be either gross (visible) or
microscopic (as defined by more than three to five red blood cells per high power
field when viewed under magnification). Gross hematuria can vary widely in
appearance, from light pink to deep red with clots. Despite the quantity of
blood in the urine being different, the types of conditions that can cause
the problem are the same, and the workup or evaluation that is needed is
People with gross hematuria usually present to their doctor
with this as a primary complaint. Microscopic hematuria, on the other hand, is
most commonly detected as part of a periodic checkup by a primary-care
The causes of gross and microscopic hematuria are similar and may result from bleeding anywhere along the urinary tract. One cannot readily distinguish between blood originating in the kidneys, ureters (the tubes that transport urine from the kidneys to the bladder), bladder, or urethra. Any degree of blood in the urine should be fully evaluated by a physician, even if it resolves spontaneously.
Infection of the urine, stemming either from the kidneys or bladder, is a common cause of microscopic hematuria. Kidney and bladder stones can cause irritation and abrasion of the urinary tract, leading to microscopic or gross hematuria. Trauma affecting any of the components of the urinary tract or the prostate can lead to bloody urine. Hematuria can also be associated with renal (or kidney) disease, as well as hematologic disorders involving the body's clotting system. Medications that increase the risk of bleeding, such as aspirin,
warfarin (Coumadin), or clopidogrel (Plavix), may also lead to bloody urine. Lastly, cancer anywhere along the urinary tract can present with hematuria.
Medical Author: Melissa Stoppler, M.D.
K. Hecht, Ph.D.
One in every 20 people develop a kidney stoneat some
point in their life. Kidney stones, sometimes called renal calculi, form within the kidney itself or
in other parts of the urinary tract.
People who have kidney stones report the sudden onset of
excruciating cramping pain in their side, groin, or abdomen. Changes in body position do
not relieve this pain. It may be so severe that it is accompanied by nausea and
vomiting. Kidney stones also characteristically cause blood in the urine. If infection is present in the urinary tract along with the stones, there may be