Causes of Primary Hyperhidrosis are not currently known. Symptoms of primary hyperhidrosis are caused by overactivity of certain sweat glands which can be triggered by things such as stress, but this does not preclude that stress is the cause of the disorder. Those with hyperhidrosis are no more prone to stress than those without it. Some studies suggest that genetics can be the cause of excessive sweating from primary hyperhidrosis, as a lot of people suffering from the disorder often have a close family member with the same condition.
Excessing sweating causes from secondary hyperhidrosis are usually because a person is suffering from an underlying health condition such as: anxiety, diabetes, obesity, alcohol abuse, heart disease, other substance abuse or medical conditions.