Anhidrosis is the inability to sweat normally. When you don't sweat (perspire), your body can't cool itself, which can lead to overheating and sometimes to heatstroke — a potentially fatal condition. Anhidrosis — sometimes called hypohidrosis — can be difficult to diagnose. Mild anhidrosis often goes unrecognized.
Dozens of factors can cause the condition, including skin trauma and certain diseases and medications. You can inherit anhidrosis or develop it later in life. Anhidrosis that affects a small part of your body usually isn't a problem and doesn't need treatment. But large areas of decreased perspiration can be life-threatening.
Treatments may depend on the condition that's causing the anhidrosis. Anhidrosis sometimes goes unrecognized until a substantial amount of heat or exertion fails to cause sweating. Overall lack of sweating can be life-threatening because the body will overheat. If the lack of sweating happens in a small area only, it is usually not as dangerous.