Discolored perspiration can be unsightly, embarrassing and expensive to remove from your clothing. There are many different causes of sweat discoloration, and therefore different treatments and solutions for the problem. It is relatively rare, but possible, for discolored perspiration to be a symptom of poison exposure or another health problem, so consult your doctor for medical advice.
Chemical poisoning may causediscolored perspiration. A study carried out at the University of Auckland, New Zealand, reported in the July 2001 issue of the "International Journal of Occupational and Environmental Health," indicated that timber workers exposed to pentachlorophenol (PCP) in the course of their work displayed symptoms and syndromes including discolored and foul-smelling sweat. Other symptoms of these workers included headaches, eye irritation, fever, respiratory tract problems and chronic fatigue syndrome. None of these symptoms could be conclusively linked to the PCP exposure specifically.
Chromhidrosis is an unusual physical condition that may cause your perspiration to appear discolored. This happens when lipofuscin -- a yellowish-brown pigment associated with aging -- becomes mixed in with your sweat. It is believed that lipofuscin occurs when free radicals cause damage to proteins and fats. Proteins and fatty acids are present in apocrine sweat; apocrine sweat glands are those that typically start working at puberty and are located mostly in your underarm area.
An article in the December 2005 issue of "Dermatology Review" indicates that pseudochromhidrosis is a form of chromhidrosis that causes sweat discoloration through external rather than internal contamination of your sweat. For example, if you work with copper, the copper may contaminate the sweat on your body and clothes, turning it blue. The article reports that flight attendants wearing red uniforms found their perspiration became red as a result of sweat interacting with dye in the uniform.
If you see sweat stains on your clothes -- most often a yellowish color -- you might naturally believe that your perspiration itself is discolored yellow. However, sweat leaves your body as a clear liquid, becoming yellow on contact with clothing through the action of bacteria. If you do not wash sweaty clothes promptly, and if you use a high temperature while washing them, it's more likely that the stain will oxidize and become yellow as a result of clothes washing.