I am having fever: what should I know?

A fever is a body response that can support the immune system while it deals with an illness. You may also notice chills, sweating, headache, muscle aches, tiredness, or reduced appetite. The number on a thermometer matters, but so does how you feel and whether symptoms are getting better or worse.

Fever can happen with many short-term illnesses, and the cause cannot be identified from temperature alone. A clinician may ask about recent travel, contact with illness, medicines, rashes, breathing symptoms, urinary symptoms, or pain in a particular area.

Rest and take regular sips of water or another suitable fluid. Wear light, comfortable clothing and keep the room at a comfortable temperature. Avoid strenuous activity and alcohol while you feel unwell. Check your temperature with a working thermometer and record when it changes, along with other symptoms.

If you use a fever-relieving medicine, follow the label or a clinician's instructions and check whether it is suitable for you. Do not combine products that contain the same ingredient. Children, older adults, pregnant people, and anyone with a long-term condition may need individual advice sooner.

Seek urgent medical help for trouble breathing, chest pain, confusion, fainting, a seizure, a severe headache with a stiff neck, blue or grey lips, or a rapidly spreading rash. Get prompt advice if you cannot keep fluids down, are passing very little urine, or feel markedly weak or drowsy.

Arrange medical advice if the fever is persistent, keeps returning, or is accompanied by worsening pain, a new rash, painful urination, or a cough that is becoming more severe. Seek advice earlier for an infant, a person with reduced immunity, or someone with a serious ongoing illness.

Ask: What causes should we consider from my symptoms and examination? Do I need testing or a follow-up check? Which fever medicine is appropriate with my other medicines or health conditions? What changes should make me seek urgent help?