A walk down a cold, windy street can send a shivery tingle up and down your body, but so can some health conditions, like the flu, kidney stones, or an underactive thyroid.

You get chills when the muscles in your body squeeze and relax to try to make heat. This sometimes happens because you’re cold, but it can also be an attempt by your immune system — the body’s defense against germs — to fight off an infection or illness.

Flu

Your body may use chills to boost its core temperature and kill off the flu virus you’ve caught. This is why fever and chills often happen at the same time. Although you may feel like you are freezing, your body temperature inside could be turned up as high as 104 F.

If flu is the cause of your chills, you might also have symptoms like:

Sore throat or cough
Runny or stuffed-up nose
Muscle aches
Fatigue
Headache
Nausea
Throwing up
Diarrhea
Most of the time, the flu goes away on its own within 2 weeks. During that time, you should rest and drink lots of fluids. Children under the age of 5, adults over 65, and anyone with a long-term health issue should see a doctor right away.

Infection

Just like with the flu virus, your body can turn on the chills in response to other infections. This may help your immune system kick in faster and work better.

Chills are a common symptom of infections like pneumonia, urinary tract infections (UTI), and malaria.

Besides chills, an infection can also cause symptoms like:

Fever
Coughing
Sore throat or mouth sores
Stuffed-up nose
Shortness of breath
Stiff neck
Pain or burning when you pee
Diarrhea
Throwing up
Belly pain
Redness, soreness, or swelling in one area

See your doctor if you have these symptoms. You may need medication to treat the infection.

Infection Due to a Kidney Stone

You might get chills because of an infection that starts when you have a kidney stone.

Sometimes minerals and salts stick together to form a hard mass inside your kidney called a kidney stone. This is more likely to happen if you don’t drink enough water each day, eat a diet that’s high in protein, or have a high body mass index (BMI.)What You Need to Know About Hepatitis B

This article is for people who have hepatitis B or may be tested for hepatitis B, their partners and family, and anyone who wants to learn more about hepatitis B. The goal of this patient education activity is to educate patients about hepatitis B and why treatment is important.

You will learn about:

What hepatitis B is

What causes hepatitis B and who’s at risk for getting it

How hepatitis B is diagnosed and what tests your doctor may do

Why treating hepatitis B is important

Questions to ask your doctor