10880 Fever

Overview

A fever means your body temperature is higher than normal — usually 38°C (100.4°F) or above when measured with a thermometer. Fever is not an illness on its own. It is a sign that your immune system has turned up the heat to fight off something, most often an infection caused by a virus or bacteria. A raised temperature is part of how the body defends itself, so a mild fever is often a normal, useful response rather than something to fear.

Yes. Fever is one of the most common reasons people contact a doctor, pharmacist or health service, and it is extremely common in young children. Most episodes are mild and get better without any special treatment.

Anyone can get a fever, but it happens most often in babies and young children because their immune systems are still learning and they pick up many infections. Older adults, pregnant women and people with a weakened immune system need to be a little more careful, because an infection can affect them more quickly. Some older adults may not raise their temperature much even when they are quite unwell.

Symptoms

Common symptoms

• Skin that feels hot to touch, especially on the chest, back or forehead
• Feeling cold, shivering or having chills at first
• Sweating and feeling clammy as the temperature comes down
• Headache and aching muscles
• Tiredness, low energy and wanting to sleep more
• Loss of appetite and feeling thirsty
• Flushed or pale face
• A faster heartbeat and faster breathing than usual
• Feeling irritable, foggy or generally 'not yourself'

Symptoms in children

• Being fussy, clingy or hard to settle
• Crying more than usual, or a cry that sounds different
• Feeding or drinking less than usual, or refusing feeds
• Fewer wet nappies or fewer trips to the toilet than normal
• Drowsiness, or being harder to wake or to interest
• A hot forehead or hot tummy with cool hands and feet
• Earache, sore throat, cough or rash alongside the fever
• A febrile seizure (a brief fit) — this happens in a small number of children and needs urgent medical advice the first time

Symptoms in older adults

• Temperature may be only slightly raised, or not raised at all, even with a serious infection
• New confusion, drowsiness or difficulty following a conversation
• A sudden drop in mobility, or unsteadiness and falls
• Not eating or drinking, or losing interest in usual activities
• Feeling unusually weak, dizzy or 'not right'
• A change in behaviour or mood that family members notice first

Causes

Main causes

• Viral infections, such as colds, flu-like illnesses and common childhood viruses
• Bacterial infections, such as ear, throat, chest, skin or urine infections
• Childhood illnesses such as chickenpox and measles
• Reaction to a vaccination, which is usually mild and short-lived
• Inflammatory conditions, where the body's own immune system causes heat and swelling
• Heat-related causes, such as heat exhaustion, too much sun, or a baby being over-wrapped
• Less commonly, other medical conditions that a doctor will look for

Risk factors

• Being a baby or young child, especially if attending childcare or nursery
• Being an older adult, particularly with other health conditions
• A weakened immune system, for example from certain illnesses or treatments
• Close contact with someone who has an infection
• Recent travel to an area where infections such as malaria are common
• Pregnancy
• Hot weather, strenuous activity in the heat, or dressing a baby too warmly

When to see a doctor

See a doctor urgently if:

• Your baby is under 3 months old and has a temperature of 38°C (100.4°F) or higher
• You or your child has a rash that does not fade when pressed with a glass
• Breathing is fast, noisy or difficult, or there is chest pain
• You feel very sleepy, confused or cannot be woken properly
• There are signs of dehydration, such as dark urine, very little urine, dry mouth or dizziness on standing
• A fever follows a fit or seizure
• A fever starts in someone having chemotherapy or with a weakened immune system

Book a routine appointment if:

• The fever has lasted more than 5 days
• The fever keeps returning after a day or two of feeling better
• You have other symptoms that worry you, such as earache, a sore throat, a cough or pain when passing urine
• You are pregnant and have a fever
• You have recently travelled abroad
• You feel unsure or anxious — it is always reasonable to ask for advice

Diagnosis

A doctor or nurse will usually start by asking about the symptoms, how long the fever has lasted, any recent travel, and any long-term conditions. They will take the temperature with a thermometer and examine the person, checking the throat, ears, chest, skin and tummy. Often this is enough to identify the likely cause, and no further tests are needed.

Tests that may be done

• A temperature reading with a digital thermometer (for a baby, an armpit reading is often used)
• A urine test, to check for a urine infection
• A throat swab, if a throat infection is suspected
• A blood test, if the cause is unclear or the person is very unwell
• A chest X-ray, if a lung infection is suspected
• Occasionally, other tests such as a sample of fluid or a scan, depending on the symptoms

What to expect at your appointment

Most appointments are quick and reassuring. The clinician will explain what they think is causing the fever and what to watch for. If they are not sure, they may arrange a review in a day or two, or ask you to come back if things change. Ask them to write down any warning signs to look out for, and make sure you know where to go if things get worse.

Treatment

The main aim of treatment is to keep the person comfortable and well hydrated while their body deals with the underlying cause. Most fevers do not need medicine at all. If the fever is making someone miserable, a pharmacist can advise on a suitable over-the-counter fever-reducing medicine for their age — always follow the label and the pharmacist's advice, and never give more than one medicine containing the same ingredient. Antibiotics only help when the cause is a bacterial infection, and a doctor will decide whether they are needed.

Self-care at home

• Drink plenty of fluids — water is best, and small frequent sips are easier than large amounts at once
• Rest as much as you need to, and avoid strenuous activity
• Wear light clothing and use a light sheet rather than heavy bedding
• Keep the room at a comfortable temperature and let fresh air in
• Do not use cold baths, ice packs or fanning directly on the skin — these can make things worse
• Check the temperature every few hours, and more often for a baby or an older adult
• Keep children off school or nursery until they feel well and the fever has settled
• Offer extra feeds to babies and young children, and watch for signs of dehydration

Medical treatments

Doctors treat the cause of the fever rather than the number on the thermometer. For viral infections, the body usually clears the infection itself and treatment is about comfort and fluids. For bacterial infections, a doctor may prescribe antibiotics — these do not work on viruses. For more serious infections, treatment may be given in hospital, sometimes through a drip, along with close monitoring. Fever-reducing medicines available from a pharmacy can ease discomfort, but they do not cure the infection and are not needed for every fever.

When is surgery considered?

Surgery is not a treatment for fever itself. Very rarely, an infection that causes fever — such as an abscess or appendicitis — may need a procedure or operation, and a hospital team would discuss this with you if it were relevant.

Living with this condition

While someone has a fever, keep things simple: fluids, rest, light clothing and regular check-ins. It helps to write down the temperature and any medicines given, with times, so you can tell a doctor clearly what has happened. Notice how the person is behaving as well as the number — are they drinking, talking, and settling when the temperature drops? Keep a note of any phone numbers for your doctor or local health service so you do not have to search for them when you are worried.

Lifestyle tips

• Build good hand hygiene into daily life for the whole household
• Keep shared surfaces, cups and towels clean when someone is unwell
• Make sure children get plenty of sleep and a balanced diet to support their immune system
• Avoid over-wrapping babies, and check their temperature if they feel hot
• Stay up to date with recommended vaccinations for your family
• Keep a working thermometer at home and learn how to use it correctly

Diet and exercise

There is no special diet for fever, but fluids are the priority — water, diluted squash, milk and soups all count. Offer small, simple meals if appetite is low, and do not worry if someone eats little for a day or two as long as they are drinking. Avoid alcohol and very sugary or caffeinated drinks, which can make dehydration worse. Rest until the fever has settled for at least 24 hours, then return to activity gradually. Children should stay home from school until they feel well enough to take part.

Mental health and emotional wellbeing

Fever can be frightening, especially in a small baby or an older relative. Broken nights and constant checking are exhausting, and it is completely normal to feel anxious. Try to take turns with another adult if you can, and remember that most fevers are short-lived and settle. If worry is stopping you sleeping or eating, or you keep feeling panicky, speak to your doctor — support is available and you do not have to cope alone. If you ever feel you cannot keep yourself safe, contact your local emergency number or a crisis line in your country straight away.

Prevention

Not every fever can be prevented, because infections are part of normal life. But you can lower the chances of catching and spreading the infections that cause fever by washing hands often, covering coughs and sneezes, keeping shared surfaces clean, and staying away from others when unwell. Staying up to date with routine vaccinations gives strong protection against several illnesses that cause fever, and avoiding overheating — especially in babies — prevents heat-related raises in temperature.

Vaccines

Routine childhood vaccinations protect against many infections that cause fever, including measles, mumps, rubella, chickenpox in some countries, and others offered by your local schedule. Adults may be offered vaccinations such as flu or other vaccines depending on their age, health and where they live. Ask your doctor or pharmacist which vaccinations are recommended for you and your family.

Screening programmes

There is no screening test for fever itself. Screening programmes exist for some of the conditions that can cause fever, such as certain infections in pregnancy, and these are offered by local health services where relevant. Your doctor can tell you what is available in your area.

Complications

If left untreated

• Dehydration, especially in babies, young children and older adults
• Febrile seizures — brief fits in young children, which are frightening but usually harmless
• The infection causing the fever spreading or becoming more serious
• A delay in treating a bacterial infection that needs antibiotics
• In older adults, confusion, falls and a faster decline in general health

Long-term outlook

The great majority of fevers get better on their own within a few days and leave no lasting effects. Fever is a normal part of how the body fights infection, and coping with it is something families do all the time. If a fever lasts longer or keeps coming back, your doctor can look for the cause and help. With sensible home care, good fluids and advice when you need it, most people recover fully and quickly.

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