Sweat rash can occur when sweat builds up on the skin, upsetting the balance of microbes which in turn causes soreness, itchiness or inflammation. It is most likely to occur as a result of sweating during exercise or warm weather, where skin rubs together (such as under arms, breasts, behind the knees or in the groin area) or where clothes rub against the skin. When it occurs between the toes, it is known as "athlete's foot".

It can be treated using a cream, spray or powder containing Hydrocortisone (HC) and an antifungal agent such as Clotrimazole.

Sweat rash associated with the groin and gential region is often referred to as Jock Rash, Jock Itch, or Dhobie Itch.