What causes chills?

Shivering creates heat when the brain's temperature control centre senses that the body needs to warm up. Chills may occur before a fever becomes obvious, during a fever, or without a fever after being in a cold environment. Infections such as influenza, pneumonia, a urinary tract infection, or a kidney infection can cause chills. In regions where these illnesses occur, malaria and dengue fever are also possible causes, especially after relevant travel or mosquito exposure. A severe infection can sometimes cause chills with confusion, marked weakness, or breathing difficulty; this needs urgent attention.

Check your temperature if you can, drink fluids, rest, and use light layers so you can adjust your comfort without overheating. Notice whether you also have cough, painful urination, back or side pain, rash, headache, vomiting, or recent travel. Do not start antibiotics or antimalarial treatment without medical advice. If chills keep returning, last beyond a short illness, or occur with a known medical condition, arrange an assessment and take a record of temperatures and other symptoms.

Seek urgent medical help for chills with confusion, fainting, severe breathlessness, blue or grey lips, a stiff neck, a rapidly spreading rash, severe pain, or difficulty staying awake. Prompt assessment is also needed for repeated shaking chills with a high temperature, dehydration, or worsening illness. After travel to a malaria-risk area, fever or chills should be assessed urgently even if symptoms seem mild. In the UAE, contact emergency services for severe or rapidly worsening symptoms.

Ask what might be causing the chills, whether you need a urine test, blood tests, or chest assessment, and which warning signs should bring you back. Mention your temperature pattern, medicines, recent travel, insect bites, and any urinary, breathing, stomach, or skin symptoms.