What is Fever?

In clinical terms, fever or pyrexia is a body temperature above the normal range (37.8°C or 100°F). It is not a disease; rather, it is a symptom of an underlying disease/infection. Fever occurs temporarily in the body as a part of our immune defence that protects the body by fighting against infections. It usually subsides on its own or after taking certain over-the-counter (OTC) medications.

What are the causes of a Fever?

The hypothalamus in the brain controls our body temperature. In certain conditions, the hypothalamus resets the body temperature higher than the normal range, causing a fever. 

Certain conditions responsible for fever include:

  • Viral, bacterial, or parasitic infections in any part of the body such as COVID-19, flu, malaria, urinary tract infections, typhoid, etc.
  • After a dose of vaccine or routine immunisation in children
  • Food poisoning
  • Autoimmune conditions like arthritis, lupus, etc.
  • Exhaustion
  • Cancers

What are the diagnosis and treatment options for a Fever?

Generally, adults measure their fever by placing a digital thermometer in the mouth or under the armpit. In children under 3 years of age, rectal temperature is taken to check the fever. If you have other symptoms, the doctor will advise a few tests to look for any underlying infection. 

The treatment of a fever involves OTC medications known as antipyretics such as paracetamol, ibuprofen, or diclofenac, to be taken every 6 hours or twice a day. Other treatments include antibiotics (as per underlying disease), fluids, and rest. 

When should you consult a doctor if you have a Fever?

If your body temperature is more than 102°F (38.9°C), persists for over 48 hours, is accompanied by other symptoms like body ache, headache, loss of appetite, etc., one should immediately consult a doctor. After a thorough medical examination, the doctor will prescribe medications or ask you to undergo some diagnostic tests to look for an underlying cause. You can consult any of our experienced doctors at Yashoda Hospitals.


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Frequently Asked Questions about Fever

A body temperature over 100°F or 37.8°C is categorised as a fever. However, the temperature range varies among children and adults:

  • In babies: 100.4°F (38°C)
  • In children: 102°F (38.9°C)
  • In adults: 103°F (39.4°C)

A low-grade fever is defined as the body's temperature ranging between 99°F-102°F (37.2°C-39.4°C). Along with a rise in the body temperature, the person may experience

  • Fatigue
  • Headache
  • Loss of appetite
  • Body aches (myalgia)
  • Chills
A low-grade fever indicates that your body is working against the infection and usually subsides on its own. It usually occurs during a common cold, stomach infections, arthritis, and lupus.

Yes, certain types of allergies, like hay fever caused by pollen or dust particles, can trigger inflammation in the body that can cause a fever.

Scarlet Fever is a type of bacterial disease accompanied by sore throat, high-grade fever, and a characteristic red rash on the body. It affects children in the age groups of 5-15 years and is treated by antibiotics.

A child's fever is considered too high if their rectal temperature exceeds 100.4°F (38°C). If a fever in the child persists after the medication, consult a paediatrician immediately.

Teething may cause a slight increase in body temperature that is not considered a fever. It usually subsides on its own or after taking paracetamol.

Yellow fever is a fatal disease caused by the mosquito Aedes aegypti. It is named yellow fever because it causes jaundice in the patients along with high-grade fever. Yellow fever is a vaccine-preventable disease that commonly occurs in African and some South American countries.

Fever after vaccination is a common occurrence. Give a liquid suspension of paracetamol 120 mg twice a day or as per the doctor's recommendation. Also, hydrate the baby with enough fluids to prevent dehydration.

No, hay fever or allergic rhinitis is a type of allergy to tiny particles present in the air, e.g. pollen, dust particles, animal dander, etc. It doesn't spread from person to person and is not contagious.

Disclaimer: The information provided herein is accurate, updated and complete as per the best practices of the Company. Please note that this information should not be treated as a replacement for physical medical consultation or advice. We do not guarantee the accuracy and the completeness of the information so provided. The absence of any information and/or warning to any drug shall not be considered and assumed as an implied assurance of the Company. We do not take any responsibility for the consequences arising out of the aforementioned information and strongly recommend you for a physical consultation in case of any queries or doubts.