What is fever?


Know the basics

What is fever?

Fever is a temporary increase in the body’s temperature in response to a disease or illness. Our body temperature doesn’t stay the same throughout the day. In fact, it’s usually higher in the afternoon. However, if your temperature is higher than 38oC, you are having a fever.

Fever usually occurs in response to an infection as with the flu or cold viruses or strep throat bacterial infection, or with inflammation that occurs with tissue injury or disease.

How common is fever?

Fever in adults is common. It is considered an important part of the body’s defense against infection. It commonly affects more females than males. Anyone can get a fever at some point in their life.

However, when the temperature rise too high, it can be dangerous and lead to serious illness. Fever in children need to be taken seriously. It can be managed by reducing your risk factors. Please discuss with your doctor for further information.

Know the symptoms

What are the symptoms of fever?

The common symptoms of fever are:

  • Feeling cold when nobody else does;
  • Shivering;
  • Your skin is hot to the touch;
  • Headache;
  • Loss of appetite;
  • Dehydration;
  • Depression;
  • Difficult concentration;
  • Sleepiness;
  • Sweating.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

You should contact your doctor if you have any of the following:

  • A fever of more than 40 degrees and cannot be treated with over-the-counter medications.
  • A fever that lasts for longer than 48 to 72 hours.
  • A serious medical illness such as a heart problem, diabetes or cystic fibrosis.
  • A rash or bruises.
  • Other symptoms such as a sore throat, headache, or cough.

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.

Know the causes

What causes fever?

Fever is the body’s common reaction to infection or disease. Fever is usually caused by:

  • Infections such as flu, sore throat, chickenpox or pneumonia;
  • Side effects of some medications;
  • Over-exposure to sun light;
  • Heat stroke;
  • Rheumatoid disease – which in a chronic disease that causes swelling and pain in the joints, tissues around the joints and other organs in human body;
  • Food poisoning;
  • Hormone disorders such as overactive thyroid disease;
  • Teething – the growth of teeth of infants and small children.

Know the risk factors

What increases my risk for fever?

There are many risk factors for fever, such as:

  • Age: children are more at risk of developing fever as their immune system is weak. Typically, chilren in preschool and elementary can have 10 colds per year with the most common symptom of rising body temperature.
  • Contact: gaining contact with a person who is sick will increase you risk of catching the infection and fever
  • Food and water: contaminated water and unclean food can be the cause for your infection and fever
  • Weak immune system.

Understand the diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is fever diagnosed?

Diagnosing a fever is quite straightforward – the patient’s temperature is taken by a device. A person is to have a fever if:

  • The temperature in the mouth is over 37.7o
  • The temperature in the rectum (anus) is over 37.5 – 38o
  • The temperature under the arm or inside the ear is over 37.2o

Make sure to take the person’s temperature when they are at rest, because physical activity can warm us up.

How is fever treated?

The treatment for fever may vary depending on the causes

  • For fever that is caused by a bacterial infection such as strep throat, doctor may advise using antibiotics
  • For fever that is caused by a viral infection such as a cold, non-steroidal anti-inflammatory drugs – such as Tylenol (Paracetamol) or naproxen (Aleve) may help ease some uncomfortable symptoms.

When you have a fever, you are likely to sweat a lot. Therefore, fluid intake is very important to prevent dehydration.

Although over-the-counter medications is very common and useful, they have no effects on treating sickness caused by hot weather or extreme exercise. If you have a heat stroke, go to the doctor immediately.

Children and teens should not take aspirin because taking too much aspirin is linked to Reye’s syndrome.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage fever?

The following lifestyles and home remedies might help you cope with health condition:

  • Good hygiene can reduce the risk of developing bacterial/ viral infection significantly. This includes washing hand before and after going to the toilet and after eating.
  • When a person have an infection, he/she should be separated from other people for a period of time to prevent spreading the viruses. Whoever is caring for the patient should wash their hands with warm water and soap.

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: May 30, 2016 | Last Modified: January 4, 2017

You might also like