Hyperhidrosis of the upper body due to heat stimulation is a disorder of excessive sweat gland secretion in the upper body caused by heat stimulation and is commonly associated with night sweats. Hyperhidrosis is a disorder in which excessive sweat gland secretion is caused by sympathetic hyperexcitation. The sympathetic nerve governs sweating throughout the body. Under normal circumstances, the sympathetic nerve regulates body temperature by controlling sweating and heat dissipation. So, what are the causes of excessive sweating in the upper body due to heat irritation? 1. Head sweating. Sweating is limited to the head. Mostly due to evil heat in the upper jiao, or damp heat in the middle jiao, due to steam, mostly seen in Yang Ming heat and damp heat. 2. Partial sweating. Commonly known as “half body sweating”. It is seen on the left or right side, upper or lower body. It is caused by wind and phlegm or wind and dampness that block the meridians, or by the lack of balance between Ying and Wei, or by the disharmony of Qi and Blood. 3. Cold sweating. Cold sweating refers to sweating with fear of cold and cold limbs. The sweating is not preceded by fever, the mouth is not thirsty, and is often accompanied by cold manifestations such as mental inactivity, pallor, loose stools, clear and long urine, sluggish pulse, and pale tongue. Mostly due to Yang deficiency and deficiency of Wei Qi, but can also be caused by fright.