In the blink of an eye, spring is here, and the breeze is sending warmth, girls and boys have taken off their heavy winter clothes and put on light clothes, so comfortable! However, some people to this season began to distress: shirt often wet, armpits often sticky, like a girl came to a period when the unpleasant feeling, and, a lift arm, shirt wet piece, really embarrassing! What is this? This is underarm hyperhidrosis. Hyperhidrosis is a common disease, epidemiological studies have found that the incidence of young people up to 0.5-1%, mostly in the armpits, hands, feet and other parts. The axillary sweat glands are divided into small sweat glands and large sweat glands. The small sweat glands are located in the dermis and are mainly governed by cholinergic nerves that secrete acetylcholine transmitters, and their secretions are mainly water. Many patients do not sweat when the sympathetic nerves are not excited, such as when they are resting or relaxing. When the weather is hot, when they exercise, or when they are stressed (sympathetic excitement), they sweat. Although hyperhidrosis does not pose a great threat to a person’s health, it can seriously affect daily life, work and social activities. So, why does Botulinum toxin A treat hyperhidrosis? Botulinum toxin A is a neurotoxin produced by Clostridium botulinum, which can specifically block the release of acetylcholine from cholinergic nerve endings, thus playing a corresponding role, and is now widely used in clinical applications, such as “facial wrinkle reduction” and “face slimming”. Physiological studies have confirmed that the secretion function of small sweat glands is governed by sympathetic acetylcholinergic nerves, and if local acetylcholine secretion is blocked, sweat gland secretion will stop. Botox underarm injections can play a role in blocking or reducing local sympathetic secretion of acetylcholine, and finally achieve the effect of stopping excessive sweating in patients with hyperhidrosis. Generally, the sweating is significantly reduced 2 to 3 days after Botox injection, and the excessive sweating basically disappears after 1 week, and the effect is maintained for about half a year, or longer in some patients. If combined with armpit odor, it will also effectively reduce the odor odor. Injections have a significant advantage over traditional thoracoscopic sympathetic nerve trunk dissection for axillary hyperhidrosis in terms of safety and convenience. Similarly, botulinum toxin injections have been shown to be effective in the treatment of hand and foot hyperhidrosis.