Excessive or uncontrollable sweating affects the hands, feet and armpits, it is called focal hyperhidrosis. Excessive sweating is often caused by anxiety, excitement, anger, or fear.
A dermatologist is a doctor who specializes in diseases of the skin, hair, nails and mucous membranes.
Remember that for the proper selection of health professional that treats excessive sweating you must consider the nature, severity and symptoms you are presenting.