Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link



The Manual's Editorial Staff

Reviewed/Revised Dec 2023
Get the full details
Topic Resources

What is measles?

Measles is a viral infection Overview of Viral Infections A virus is a microorganism, a tiny living organism. Other common microorganisms include bacteria. Viruses are much smaller than bacteria and can be seen only with the most powerful microscopes... read more . It used to be very common in children in the United States. Measles is now rare in the United States because it's prevented by routine childhood vaccines. In parts of the world where fewer children are vaccinated, measles is still common.

What causes measles?

Measles is caused by a virus. Healthy children who haven't had the vaccine can get measles just by breathing in the virus after someone with measles coughs or sneezes near them.

What are the symptoms of measles?

The first symptoms start 7 to 14 days after infection:

  • Fever

  • Runny nose

  • Hacking cough

  • Red eyes

  • Sometimes, sensitivity to bright light

  • Tiny red spots with white or bluish-white centers inside the mouth

  • Sore throat

About 3 to 5 days later, your child may have:

What problems does measles cause?

How can doctors tell if my child has measles?

Doctors will do a physical exam. They'll look for:

  • Measles rash

  • Tiny red spots with blue or bluish-white centers in the mouth (Koplik spots)

Doctors will do blood tests to know for sure if your child has measles. If your child does, they'll tell public health officials, who will try to keep measles from spreading to too many people in your area.

How do doctors treat measles?

There's no treatment that will cure the measles. Have your child rest while the virus runs its course.

To help your child, you can:

How can I prevent measles?

  • Children get 2 measles shots total, at age 12 to 15 months and at age 4 to 6 years

  • Children as young as 6 months can get their first shot if needed, such as during a measles outbreak or before traveling outside the United States

  • The measles vaccine is part of the MMR shot, which is a vaccine that also protects against mumps and rubella

  • The MMR shot doesn’t cause autism

  • Some people may have a mild fever and rash after getting the vaccine

  • Certain people shouldn’t get the MMR shot, including pregnant women and people who are very sick or have a weak immune system

Drugs Mentioned In This Article

Generic Name Select Brand Names
7T Gummy ES, Acephen, Aceta, Actamin, Adult Pain Relief, Anacin Aspirin Free, Aphen, Apra, Children's Acetaminophen, Children's Pain & Fever , Children's Pain Relief, Comtrex Sore Throat Relief, ED-APAP, ElixSure Fever/Pain, Feverall, Genapap, Genebs, Goody's Back & Body Pain, Infantaire, Infants' Acetaminophen, LIQUID PAIN RELIEF, Little Fevers, Little Remedies Infant Fever + Pain Reliever, Mapap, Mapap Arthritis Pain, Mapap Infants, Mapap Junior, M-PAP, Nortemp, Ofirmev, Pain & Fever , Pain and Fever , PAIN RELIEF , PAIN RELIEF Extra Strength, Panadol, PediaCare Children's Fever Reducer/Pain Reliever, PediaCare Children's Smooth Metls Fever Reducer/Pain Reliever, PediaCare Infant's Fever Reducer/Pain Reliever, Pediaphen, PHARBETOL, Plus PHARMA, Q-Pap, Q-Pap Extra Strength, Silapap, Triaminic Fever Reducer and Pain Reliever, Triaminic Infant Fever Reducer and Pain Reliever, Tylenol, Tylenol 8 Hour, Tylenol 8 Hour Arthritis Pain, Tylenol 8 Hour Muscle Aches & Pain, Tylenol Arthritis Pain, Tylenol Children's, Tylenol Children's Pain+Fever, Tylenol CrushableTablet, Tylenol Extra Strength, Tylenol Infants', Tylenol Infants Pain + Fever, Tylenol Junior Strength, Tylenol Pain + Fever, Tylenol Regular Strength, Tylenol Sore Throat, XS No Aspirin, XS Pain Reliever
Advil, Advil Children's, Advil Children's Fever, Advil Infants', Advil Junior Strength, Advil Migraine, Caldolor, Children's Ibuprofen, ElixSure IB, Genpril , Ibren , IBU, Ibupak, Midol, Midol Cramps and Body Aches, Motrin, Motrin Children's, Motrin IB, Motrin Infants', Motrin Junior Strength, Motrin Migraine Pain, PediaCare Children's Pain Reliever/Fever Reducer IB, PediaCare Infants' Pain Reliever/Fever Reducer IB, Samson-8, Toxicology Saliva Collection
A Mulsin, A-Caro-25, Aquasol A, Dofsol-A
quiz link

Test your knowledge

Take a Quiz!