Causes of excessive sweating include an overactive thyroid, low blood sugar and emotional distress, according to Healthgrades. The consumption of caffeine, alcohol and spicy foods may also cause someone to sweat more than usual.
Around 2 to 3 percent of the population experiences hyperhidrosis, a medical condition in which sweat glands produce perspiration without a reason, reports WebMD. There are two types of hyperhidrosis: primary and secondary. People with primary hyperhidrosis sweat profusely from the hands, feet, face and underarms. Secondary hyperhidrosis causes profuse sweating all over the body, and secondary hyperhidrosis is more likely to cause sweating while asleep.