Your doctor will check for a congested nose, red eyes, Koplik's spots and the typical measles rash. He or she will ask if you have been traveling outside the country or have been exposed to anyone with measles or an undiagnosed rash. Even if you did not have face-to-face contact with an infected person, your doctor will want to know if you go to the same school, live in the same household or dormitory or work in the same building. Your doctor will check your medical records to see if and when you were immunized against measles, and the number of doses of measles vaccine. These are given as part of the measles-mumps-rubella vaccine (MMR) shot.
To confirm the diagnosis, your doctor may order blood tests to look for specific antibodies that fight against the measles virus. Antibodies are made by the immune system to protect against an infection.