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 (blood cells only visible through a microscope). Gross hematuria can vary widely in
appearance, from light pink to deep red with clots. Although the amount of
blood in the urine may be different, the types of conditions that can cause
the problem are the same, and require the same kind of workup or evaluation.
People with gross hematuria
will visit their doctor
with this as a primary complaint. People who have microscopic hematuria, on the other hand,
will be unaware of a problem and their condition will most commonly be 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,
(often called a urinary tract infection or UTI) stemming either from the kidneys or bladder, is a common cause of microscopic hematuria.
Urine is naturally sterile and should not contain bacteria.
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 (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