Common causes of excessive sweating under the arms include emotions and heat, but people with the disorder experience sweating in cool weather and with calm dispositions, according to MedicineNet. Otherwise healthy individuals often suffer axillary hyperhidrosis, or excessive underarm sweating. Patients with metabolic and neurologic diseases may sweat excessively.
Treatments for axillary hyperhidrosis include nonprescription antiperspirants containing aluminum chloride and doctor-prescribed antiperspirants containing aluminum chloride hexahydrate, notes MedicineNet. Patients apply the prescription medication under the arms nightly for up to 10 nights, and the aluminum salts block the sweat ducts. Some irritation may occur. Other options, such as anticholinergics that patients take orally, can suppress sweating. Severe cases may require laser, ultrasound, microwave or surgical treatments.