Underarm sweating or hyperhidrosis is the medical term for excessive sweating. It can occur on the palms, feet, face and armpits. The cause is unknown but a genetic predisposition does exist.
Step 1 - Cleanse
Cleansing will help in eliminating the smell of the sweat but does not offer any respite from sweating.
Step 2 - Treatment
There are many treatments for Hyperhidrosis, which include antiperspirants with high aluminum content (which can be found at the pharmacists counter), dress shields or injections. See your doctor if you have tried all the available treatments that can be found at stores.