Hyperhidrosis is excessive sweating that is more than what is needed to regulate body temperature. About 7 million Americans suffer from hyperhidrosis, a disorder that often goes undiagnosed. Hyperhidrosis sufferers often feel a loss of control because the sweating happens independently—without a high body temperature or highly charged emotional situation. The condition may make you avoid social situations, especially when they involve shaking hands. Anxiety can make hyperhidrosis worse. The condition can also be triggered by certain foods and drinks, nicotine, caffeine, and some smells.