This article explains possible causes of chills, how to treat them, and when to contact a doctor.

Chills can result from a wide variety of conditions.
Exposure to cold
Exposure to cold temperatures can cause chills as muscles contract and relax to warm the body.
Hypothyroidism
Hypothyroidism occurs when the thyroid gland is unable to produce sufficient amounts of thyroid hormones. According to the National Institute of Diabetes and Digestive and Kidney Diseases, people with hypothyroidism can be more sensitive to cold temperatures. This increases the likelihood of experiencing chills.
Learn more about hypothyroidism here.
Infections
Many types of infection, including bacterial, viral, and fungal, may cause chills.
Infections that may cause chills include:
- bacterial or viral gastroenteritis
- bronchitis
- common cold
- ear infection
- infectious mononucleosis
- flu
- meningitis, inflammation of the membrane around the brain and spinal cord
- pneumonia
- strep throat
- urinary tract infection (UTI)
- malaria
Chills and fever commonly occur alongside each other, and both can be symptoms of infections. Part of your body’s response to infection is to raise your body temperature,
Most pathogens that cause infection survive best at an average body temperature. Therefore, a fever can help remove or prevent the spread of infectious pathogens. Chills result from the rapid contraction and relaxation of the muscles to increase body temperature.
Inflammatory conditions
Chills can result from various inflammatory conditions, including:
- reaction to a blood transfusion
- inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis
- systemic lupus erythematosus, a disorder in which the body interferes with its own healthy cells and tissues
Malignant conditions
Some cancers, such as non-Hodgkin lymphoma or leukemia, can cause chills. In addition, cancer treatments, such as chemotherapy or immunotherapy, can cause flu-like symptoms. These may include chills, fever, and nausea.
Treating chills generally involves addressing the underlying cause. For example, people in a cold environment should move to a warmer environment or put on additional protective clothing.
People with hypothyroidism usually need thyroid hormone replacement from medications such as levothyroxine. Doctors may also recommend dietary changes.
Doctors typically prescribe antibiotics for certain bacterial infections, such as UTIs or strep throat.
Antiviral medications can help treat viral infections. Antifungal drugs can help people with fungal infections.
Over-the-counter medications can relieve chills and other symptoms of common conditions, like the flu or cold. These medications include ibuprofen (Advil) or acetaminophen (Tylenol).
People with IBD or other inflammatory disorders
Chills often occur with other symptoms, including:
- aches and pains
- cough
- diarrhea
- earache
- fever
- general feeling of illness
- hot, dry skin
- sweating
- lethargy
- nausea
- rash
- vomiting
Sometimes, chills can be a symptom of a serious or life threatening condition. Seek prompt medical care if symptoms persist for more than 2 days or cause you concern.
In some cases, serious or life threatening conditions cause chills. Without treatment, these conditions can result in severe complications, including:
- brain damage from an extremely high fever
- dehydration from reduced fluid intake, fever, and increased sweating
- dehydration from diarrhea or vomiting
- seizures
- shock, coma, and organ failure
It is important to follow your treatment plan to reduce the risk of complications.
Chills are often mild in nature. They usually are not associated with serious medical conditions.
In some cases, however, chills may occur with other symptoms that do indicate a serious or life threatening condition. These conditions require immediate evaluation in an emergency setting. Seek immediate medical care (call 911) if you have chills with any of these symptoms:
- change in level of consciousness or alertness, such as passing out or unresponsiveness
- fever higher than 101oF (38oC)
- pale or bluish coloration of the skin, lips, or nails
- persistent watery diarrhea, possibly with blood
- respiratory problems, such as difficulty breathing or wheezing
- seizure
- stiff neck, possibly with nausea, vomiting, and confusion
- severe headache
These are a few other questions people commonly ask about chills. Dr. Avi Varma has reviewed the answers.
Can COVID cause chills?
According to the
What does having chills without a fever mean?
You may experience chills without a fever if you are in a cold environment. Additionally, people with hypothyroidism can have trouble tolerating cold temperatures.
What is the best medicine for chills?
Treating chills depends on the underlying cause. For example, your doctor may prescribe antibiotics to clear certain bacterial infections and treat your symptoms. Contact your doctor to determine the best way to relieve chills.
When should I worry about chills?
If your chills last for more than a few days or do not improve with self-care, contact your doctor. Chills may be a symptom of a serious underlying condition.
Chills can be a symptom of conditions including exposure to cold, hypothyroidism, infections, or malignant conditions. Treating chills depends on addressing the underlying condition or moving to a warmer environment.
Contact your doctor if you are experiencing severe or persistent chills. Your doctor can help you determine the underlying cause and an appropriate treatment plan.