causes of excessive underarm sweating
Localized Sweating: Primary Focal Hyperhidrosis. The most common cause of excessive sweating is called primary focal hyperhidrosis. This form of hyperhidrosis affects about 1% to 3% of the population, and usually starts in childhood or adolescence.1 | 2 | 3 | 4.xcessive sweating is also more common in people who are overweight or out of shape. The good news is that most cases of excessive sweating are harmless. If you are worried about how much you sweat, here's information to help you decide if you should see a doctor for a medical diagnosis.