Chills

Category: General & Whole-Body Symptoms · All general symptoms

What it can feel like

Chills are waves of feeling cold with shivering or shaking, even when the room is warm. They often arrive just before or during a fever, as the body raises its temperature, and the teeth-chattering shake that comes with them is sometimes called a rigor.

Possible causes

A symptom can have many causes, and most are not serious. The lists below group conditions this symptom can be associated with — common causes first. They are possibilities to discuss with a clinician, not a diagnosis.

Common causes

Chills can be associated with the start of infections such as flu, chest infections, urine infections and tummy bugs, and with simply being cold in cold weather.

Other possible causes

Repeated shaking chills can also be associated with infections of the kidney or gallbladder, with malaria after travel to affected regions, or with infection entering the bloodstream, which is an emergency.

Red flags — when to seek help promptly

Shaking chills with confusion, breathlessness, a racing heart or feeling extremely unwell
Chills in someone whose immune system is weakened, for example during chemotherapy
Chills with a stiff neck, a non-fading rash or drowsiness
Chills that keep coming back over several days

What a clinician may do

A clinician will ask about fever, travel, recent infections and medicines, examine you, and check your temperature and pulse. Blood tests, a urine test and sometimes blood cultures or imaging are used to look for the source of the infection.

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Frequently asked questions

Are chills always a sign of infection?

Not always — chills are simply the body's way of generating heat, and they can happen with a cold environment or anxiety. But new chills with fever are most often the start of an infection, and shaking rigors in particular deserve prompt assessment.

What should I do when the chills start?

Keep warm with layers you can remove as the fever peaks, drink fluids, and note the time and any other symptoms. If shaking chills come with feeling very unwell, seek medical help the same day.

Related symptoms — General & Whole-Body Symptoms

Excessive sweating Excessive thirst Fatigue Feeling cold all the time Feeling generally unwell (malaise)Fever

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Please note: This page is educational information about a symptom. A symptom alone cannot diagnose any condition, and the causes listed here are possibilities, not a diagnosis. If you are worried about a symptom — especially one that is new, severe, getting worse or not going away — please see your own clinician, who can examine you and arrange tests. In an emergency, call your local emergency number.