Excessive underarm sweating is a very common condition but often not recognized or treated. Medical definitions have looked at quantifying the amount of sweat produced but for all practical purposes any sweating that interferes with normal living is considered as hyperhidrosis.
Sweat is your body's temperature regulator. Severe underarm sweating is usually due to overactive sweat glands. In severe primary axillary hyperhidrosis, sweating significantly exceeds the body's normal requirements for cooling. Sometimes excessive sweating is due to other medical causes. As with any medical condition, a diagnosis must first be made to exclude and treat any underlying cause. Diagnosis is usually made on clinical picture but sometimes further testing is necessary.
Treatment options are-
General measures such as daily showering, wearing loose cloths made of natural fibre and frequent change of clothing etc and antiperspirants which you can buy over the counter. There are some stronger aluminium chloride based antiperspirants which help but can sometimes cause irritation. Iontophoresis [electrical stimulation] can be cumbersome.
One very straightforward and effective option is botulinum toxin injections which is a prescription only medication. A starch iodine test is carried out to accurately map the overactive sweat glands and then injections are made into layers of the skin to block the nerve signals from reaching the sweat glands. Duration of response can be variable but I find most of our patients to be dry for up to one year.
There are other more invasive options such as curettage or removal of sweat glands. Rarely keyhole surgery is used to remove nerve ganglions from inside the thorax [sympathectomy]. This is a major undertaking and side-effects can be more unpleasant than the original condition so I do not recommend this for most people. Recently liposuction laser and vaser devices have been used to destroy the sweat glands under local anaesthesia. This would be a very attractive option if long term results are favourable.