Types of Hematuria

There are two types of hematuria, microscopic and gross (or macroscopic). In microscopic hematuria, the amount of blood in the urine is so small that it can be seen only under a microscope.

A small number of people experience microscopic hematuria that has no discernible cause (idiopathic hematuria). These people normally excrete a higher number of red blood cells.

In gross hematuria the urine is pink, red, or dark brown and may contain small or large blood clots. The amount of blood in the urine does not necessarily indicate the seriousness of the underlying problem. As little as 1 milliliter (0.03 ounces) of blood will turn the urine red.

"Joggers hematuria" results from repeated jarring of the bladder during jogging or long-distance running.

Reddish urine that is not caused by blood in the urine is called pseudohematuria. Excessive consumption of beets, berries, or rhubarb; food coloring; and pain medications (e.g., nonsteroidal anti-inflammatory drugs [NSAIDs] such as aspirin) and certain laxatives (e.g., Ex-lax) can produce pink or reddish urine.

Publication Review By: Stacy J. Childs, M.D., Stanley J. Swierzewski, III, M.D.

Published: 14 Jun 1998

Last Modified: 18 Sep 2015