Chills but no fever: what it can mean

Chills are an involuntary attempt to generate heat. Cold surroundings, wet clothing, anxiety, exhaustion or a low blood sugar level can cause them even when your temperature is normal. Some infections begin with chills before fever appears, and a temperature reading can be normal after fever medicine. A urinary infection, kidney infection, influenza, malaria, dengue fever or pneumonia may present with other clues, such as pain, cough, vomiting, rash, burning urine or recent travel.

The symptom alone cannot identify the cause. Record when it starts, how long it lasts, your temperature, recent medicines, food intake and any new symptoms.

Move to a comfortable warm place, change out of damp clothes and use a light blanket. Sip fluids and eat a small snack if you may have missed a meal and can safely eat. Rest, check your temperature with a reliable thermometer, and avoid strenuous activity until the episode settles. Do not take antibiotics left over from another illness. Arrange a medical review if episodes recur, continue, or occur with urinary, breathing, abdominal or travel-related symptoms.

Seek urgent care for confusion, fainting, severe breathlessness, blue or grey lips, a rapidly worsening illness, severe weakness, or cold clammy skin with a fast heartbeat. Get prompt medical advice for chills with a stiff neck, severe headache, persistent vomiting, new rash, flank pain, painful urination or recent travel to a malaria area. These warning signs warrant attention even without fever.

Ask whether your medicines, thyroid function, blood sugar, circulation or an infection could explain the episodes, and which tests are appropriate if they continue.