Excessive sweating or hyperhidrosis is when the amount of sweat is abnormally higher than that required for a normal heat balance. 

There are two types of excessive sweating: primary (the most common type), which affects the palms of the hands, soles of the feet and/or underarms; and secondary (caused by an underlying condition such as a genetic syndrome, infection, tumour or medication). The latter type of sweating may be localised or general.