The Causes of Focal Hyperhidrosis

Scientists aren’t sure how or why focal hyperhidrosis (excessive sweating of the hands, feet, face, and underarms) occurs. Genetics appears to be at least partially involved. Some 30 to 50 percent of individuals with focal hyperhidrosis report having another family member with the condition.

Individuals with focal hyperhidrosis do not have more or larger sweat glands than other people. The condition seems instead to represent a dysfunctioning of the autonomic nervous system, which relays messages between the brain and the sweat glands. For some reason, the nerves overstimulate the glands. But precisely what causes that dysfunction remains a mystery.

Certain factors can exacerbate sweating in people with focal hyperhidrosis, including intense emotions (anxiety, excitement) and various foods and drinks, especially caffeinated ones. Smoking can also help trigger an overstimulation of the sweat glands. Often, though the sweating begins for seemingly no reason at all.

The Causes of Generalized Hyperhidrosis

A variety of medical conditions can cause generalized hyperhidrosis (sweating over most of the body), including heart disease, cancer, an overactive thyroid (hyperthyroidism), Parkinson’s disease, and low blood sugar (hypoglycemia). Menopause can also trigger greater-than-normal sweating in some women. Because excessive sweating can be a symptom of an underlying illness, it’s important that you discuss it with your doctor.

Certain prescription and non-prescriptions drugs may also cause generalized sweating, including pain medications and antidepressants. Be sure to tell your physician if you develop uncomfortable excessive sweating or “night sweats” after starting a new medication. Your doctor may either recommend that you lower the dose or switch you to a different medication.