fever screening test preparation

Overview

A fever screening test is a set of checks and laboratory tests used to find out what is causing a high body temperature (fever). It may include a physical exam, blood tests, urine tests, or swabs from the nose or throat. The goal is to identify an infection or other condition so the right treatment can be started.

Yes. Fever is one of the most common reasons people visit a doctor. Fever screening tests are done frequently in clinics, emergency departments, and during hospital stays.

Anyone can have a fever. Fever screening tests are used for people of all ages, from babies to older adults, whenever a fever needs to be investigated.

Symptoms

Common symptoms

• Measured temperature of 38°C (100.4°F) or higher
• Chills and shivering
• Feeling hot or sweaty
• Headache
• Muscle aches

Symptoms in children

• Fussiness or irritability
• Poor feeding or drinking
• Flushed, hot skin
• Trouble sleeping
• Seizures (febrile seizures) in some cases

Symptoms in older adults

• A lower fever than in younger people — even 37.5°C may be significant
• Confusion or change in mental state
• Weakness or falls
• Loss of appetite
• Decreased activity

Causes

Main causes

• Viral infections (such as colds, flu, COVID-19)
• Bacterial infections (such as urinary tract infections, pneumonia, strep throat)
• Inflammatory conditions (like rheumatoid arthritis or lupus)
• Heat exhaustion or heatstroke
• Reaction to a medicine or vaccine

Risk factors

• Weakened immune system (from chemotherapy, HIV, or long-term steroid use)
• Recent surgery or hospital stay
• Exposure to someone with an infectious disease
• Travel to areas with tropical diseases
• Very young age (infants) or older age (over 65)

When to see a doctor

See a doctor urgently if:

• Fever above 39.5°C (103°F) that does not come down with rest and fluids
• Fever with a severe headache, stiff neck, or sensitivity to light
• Fever with a rapidly spreading rash
• Fever in a child who is very drowsy or difficult to wake
• Fever in an older adult with confusion or fall

Book a routine appointment if:

• Persistent low-grade fever (around 37.5–38°C) that lasts more than a week
• Unexplained fever that comes and goes
• Fever with weight loss or night sweats

Diagnosis

A healthcare provider will ask about your symptoms, travel history, and recent exposures. They will measure your temperature and check your heart rate and breathing. Based on your age and health, they may recommend one or more tests to find the cause of the fever.

Tests that may be done

• Complete blood count (CBC) — a blood test that looks for signs of infection
• Urine test — to check for a urinary tract infection
• Throat or nose swab — to test for viruses like flu or COVID-19
• Blood culture — to grow bacteria from a blood sample if a serious bloodstream infection is suspected
• Chest X-ray — if pneumonia is a possibility

What to expect at your appointment

For most tests, you will have a blood sample taken from your arm or a swab gently placed in your nose or throat. The procedures are quick and cause only brief discomfort. You may be asked to provide a urine sample. No special preparation is usually needed, but follow any instructions your healthcare provider gives you — for example, not eating or drinking before certain blood tests.

Treatment

Treatment for fever depends on the underlying cause found by the screening tests. In many cases, the fever will go away on its own as the body fights the infection. Medicines may be used to bring down a high fever or to treat the infection itself, but only when prescribed or recommended by a healthcare professional.

Self-care at home

• Rest as much as possible
• Drink plenty of clear fluids (water, clear soups) to stay hydrated
• Keep the room at a comfortable temperature
• Wear lightweight clothing and use a light blanket
• Use a cool (not cold) cloth on your forehead

Medical treatments

If an infection is found, your healthcare provider may prescribe antibiotics for a bacterial infection or antiviral medicines for certain viral infections. For fever relief, over-the-counter fever reducers (such as paracetamol or ibuprofen) can be used according to package directions, but always ask your doctor or pharmacist which one is right for you, especially for children or if you have other health conditions. Do not give aspirin to children or teenagers because of the risk of Reye's syndrome.

When is surgery considered?

Surgery is rarely needed for fever itself. It may be required if the fever is caused by a condition that needs surgical treatment, such as an abscess (a pocket of pus) that needs to be drained.

Living with this condition

While waiting for test results or recovering at home, monitor your temperature a few times each day. Keep a diary of symptoms to share with your doctor. Avoid going to work, school, or crowded places until you know the cause and are no longer infectious.

Lifestyle tips

• Get plenty of rest
• Stay well hydrated
• Avoid alcohol and smoking
• Wash hands frequently to prevent spreading infection

Diet and exercise

Eat light, nutritious meals if you have an appetite. If not, focus on fluids. Avoid strenuous exercise until the fever is gone and you feel fully recovered.

Mental health and emotional wellbeing

Having an unexplained fever or a serious infection can cause anxiety or stress. It is normal to feel worried. Talking to family or friends, practicing deep breathing, and keeping in touch with your healthcare team can help. If you feel overwhelmed, reach out to a mental health professional.

Prevention

Many causes of fever can be prevented with good hygiene, vaccinations, and avoiding contact with people who are sick. Not all fevers are preventable, but you can reduce your risk.

Vaccines

Vaccinations are available for many infections that cause fever, such as influenza, pneumonia, COVID-19, and meningitis. Ask your healthcare provider which vaccines are recommended for you and your family.

Screening programmes

There are no routine screening tests for fever itself. However, if you have a condition that weakens your immune system, your doctor may recommend regular check-ups to catch infections early.

Complications

If left untreated

• Infection may spread to other parts of the body (e.g., sepsis from a urinary tract infection)
• High fever in children can sometimes cause febrile seizures
• Dehydration from not drinking enough fluids
• Organ damage if the underlying infection is not treated properly

Long-term outlook

Most fevers go away without causing lasting problems. With proper diagnosis and treatment, even serious infections can be managed successfully. Your healthcare team will guide you on the best steps for your situation.

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