What Are the Symptoms of Measles?

A closer look at the early warning signs and possible complications as cases in the U.S. rise

Rachel Nania,

AARP

Comments

Published February 27, 2026

medical illustration featuring a magnifying glass over viral cells, a vaccine syringe, and a globe showing red outbreak spots over North America. Abstract red and blue pill shapes are scattered around the central healthcare icons

Naomi Elliott

At first, it might look like a bad cold — or maybe the flu. A runny nose is common; so is a cough and a high fever. But red, watery, crusty eyes might be your first clue that this isn’t your everyday respiratory infection. Maybe it’s measles.

Cases of the disease are rising in the U.S. As of Feb. 26, 1,136 measles cases have been reported in 2026. Last year, there were 2,281 cases, the highest annual count in more than 30 years.

Most Americans are vaccinated against measles, but declining vaccination rates are leaving more individuals — including adults — vulnerable to infection. A big reason: If you’re not protected, it’s really easy to catch. Measles is one of the most contagious of all infections.

“If you’re in a room with 100 people and one person came into the room with measles, 90-plus percent of those people who were not vaccinated and would have never seen [measles] before would get measles,” says Dr. Ronald L. Cook, chief health officer and professor of family medicine at Texas Tech University Health Sciences Center in Lubbock, Texas.

Here’s what the symptoms look like if you’re exposed.

A full-body rash almost always appears

The early warning signs that you’re sick — the fever, cough, runny nose and red eyes — typically show up seven to 14 days after exposure to the virus, which can linger as tiny droplets in the air for up to two hours, even after the infected person leaves the room.

6 common symptoms of measles

High fever
Cough
Runny nose
Red, watery eyes
White spots inside the mouth
A red rash that spreads from the top down

Source: Centers for Disease Control and Prevention

A few days after you start feeling crummy, you might notice tiny white spots — called Koplik spots — inside your mouth. “Those are just the viral outbreak inside the mouth, and so you get these little shallow ulcers,” Cook says.

Then you’ll likely see a rash of flat red spots spreading from the top of your body down to the bottom. “It’s almost like a paint can pouring over somebody’s head, and it goes head downward, and then it disappears in the opposite direction,” says Dr. Jordan Marmet, a hospitalist and associate professor of pediatrics at the University of Minnesota.

Almost everyone gets this rash; however, it can be harder to spot in people with darker skin tones.

Older adults are at higher risk of measles complications

Some people develop complications from measles, and adults over 20 and those with weakened immune systems are at higher risk, according to the Centers for Disease Control and Prevention (CDC). About 1 in 5 unvaccinated people in the U.S. who get measles are hospitalized.

Complications can include pneumonia, ear infections, blindness, encephalitis (swelling of the brain) and a rare but fatal disease of the central nervous system known as subacute sclerosing panencephalitis.

Most Popular

Older adults are also more likely to develop hepatitis or liver problems related to a measles infection, says Dr. Stephen Thacker, an infectious disease specialist and associate professor of pediatrics at the Medical University of South Carolina in Charleston.

That’s when you see people get sicker — when complications arise, Marmet says. “Someone who is elderly and has other underlying health issues … or immune issues is more likely to get sicker with it,” he explains.

There is no antiviral medication for measles to shorten the length of the illness, like there is for the flu and COVID. Treatment for measles generally focuses on easing symptoms.

Protecting yourself from measles

Doctors say the best way to protect yourself from the disease and any potential complications is to get vaccinated.

“There are uncommon but, in my opinion, very impactful side effects [from measles], and the only way to prevent them is to not be infected,” Thacker says.

Two doses of the measles vaccine are 97 percent effective against the virus; one dose is 93 percent effective, according to the CDC.

When overall measles activity is low, this level of vaccine effectiveness is great news, Marmet explains. Still, roughly 3 percent of vaccinated individuals can develop the disease, and during periods of higher transmission, that proportion can amount to a notable number of cases. A small number of measles cases reported so far this year have occurred in vaccinated individuals, CDC data shows. Roughly 4 percent of cases have been in people who have had one dose of the vaccine; about 4 percent have occurred in people with two doses.

Can’t remember if you’ve had the vaccine? If you were born before 1957, “we generally think that you’ve been naturally infected,” Thacker says. “And for the vast, vast, vast majority of us, that provides lifelong immunity.”

If you were born between 1957 and 1967, “our vaccine strategy provided potentially less durable and long-lasting protection,” Thacker says. “So if you’re in that age range, connecting with your health care provider to see if it makes sense to receive a booster vaccination would not be unreasonable at all.”

The CDC recommends re-vaccinating anyone who received a measles vaccine of unknown type or the inactivated measles vaccine during these years.

Thacker emphasizes that there is no harm in getting another dose of the measles vaccine.

%{postComment}%