Measles is a highly contagious disease caused by a virus. It's also called rubeola (say "roo-bee-OH-luh"). Measles can cause serious illness or death, especially in young children and people who have not been vaccinated.

Measles travels through the air when an infected person coughs, sneezes, or breathes. The virus can stay in a room for up to 2 hours after an infected person has left. A person with measles can spread it to others starting 4 days before a rash appears and for 4 days after. It's one of the most contagious diseases. About 9 out of 10 people who are not immune may get measles if they are exposed.

Symptoms usually begin 7 to 14 days after exposure. But it can take up to 21 days for symptoms to begin. Early signs include:

• A high fever.
• A cough.
• A runny nose.
• Red, watery eyes.

After a few days, small white spots may appear inside the mouth. These spots are a key early sign. A blotchy rash usually follows 3 to 5 days after the first symptoms. It starts on the face and spreads down the body. The rash may appear pink or red on lighter skin and purple, brown, or gray on darker skin. A fever can reach 104°F or higher.

Measles can lead to serious problems. About 1 in 5 unvaccinated people in the United States who get measles need hospital care. Possible problems include ear infections that may cause hearing loss. Measles also can cause pneumonia and swelling of the brain, called encephalitis (say "in-seh-fuh-LY-tus"). This can lead to seizures or lasting brain damage. In some cases, measles can cause death. Young children and people who are older than 20, who are pregnant, or who have weakened immune systems are more likely to become seriously ill.

Your doctor may diagnose measles based on a physical exam and health history. You may also get a lab test to confirm the diagnosis. If you think you may have measles, call your doctor's office first. They will make special arrangement for you. Since measles is very contagious, it is important to not expose other patients or staff to measles.

There is no medicine that cures measles. Treatment focuses on managing symptoms. Rest and fluids help your body recover and prevent dehydration. Acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) can lower fever and ease pain. Do not give aspirin to children and teens. It has been linked to Reye syndrome, a rare but serious illness.

Your doctor may suggest vitamin A supplements, especially for young children, since low vitamin A levels are linked to more severe illness. Vitamin A does not prevent measles. It is not a substitute for vaccination.

The best way to prevent measles is the measles vaccine. Two doses protect about 97 out of 100 people. Children usually get the first dose at 12 to 15 months and a second dose at 4 to 6 years. Infants ages 6 to 11 months may get a measles vaccine during an outbreak or before travel. If you aren't sure if you have had the vaccine, talk to your doctor. Check if your measles vaccine is current before traveling to another country.

If you think you were exposed to measles and aren't vaccinated, contact your doctor right away. This can help lower your risk of getting sick. Getting the measles vaccine within 72 hours (3 days) of exposure may reduce the chance of illness. This may be done for infants and children 6 months or older and adults who aren't pregnant or don't have a weakened immune system.

A treatment called immune globulin (IG), given within 6 days of exposure, may be an option for certain people who can't get the measles vaccine. These include infants younger than 6 months old and people who have weakened immune systems or who are pregnant. IG is made from donated blood. It helps the body fight infection.

If you are exposed and not vaccinated, you may need to stay home for up to 21 days after your last exposure. During this time, avoid public places and watch for symptoms such as fever, cough, runny nose, rash, and red eyes. If you get symptoms, call ahead before going to a clinic or doctor's office. This can help prevent spreading measles to others.