The symptoms of hand, foot, and mouth disease usually take between 3 and 7 days to appear. This is called the incubation period. The disease lasts for around a week to 10 days and often resolves completely on its own without treatment. While most signs and symptoms of HFMD clear within 7 to 10 days, children younger than 2 years of age may be sick longer. It can take more time for their bodies to get rid of the virus.