Fever, also known as pyrexia, high temperature or high fever is the body’s normal reaction to a variety of conditions, infections and the most common medical symptom. Fever is the febrile response and defined as having a temperature above the normal range 98.6F (37C). Also Read: How To Prevent Highly Contagious Viral Fevers

It is mostly a side effect of ailments like flu, influenza, cold and it is an indication that the immune system is working hard to combat an infection or illness. Generally, fever set off when the immune system produces more white blood cells to battle an infection, increased white blood cells stimulate the brain to heat the body up and result in fever. The body reacts to this and tries to cool itself off by constricting the blood flow to the skin and contracting muscles, which cause chills, body and muscle aches. Also Read: Influenza Virus: Debunking Common Myths About The Contagious Disease

The normal body temperature ranges from 97F to 98.7F (36.1C to 37.2C), if your body temperature rises above this then you may have a fever.

Types Of Fever

  1. A low-grade fever happens when the body temperature rises to 100.4F (38C)
  2. Moderate fever if the temperature rises above 102.2-104F or 39.1-40C
  3. High-grade fever indicates if the body temperature is 104F (39.4C) or above.
  4. Hyperpyrexia, if the temperature is above 106F or 41.1C

Generally, most fevers settle on their own within 1- 3 days. However, persistent or continuous fever may start or reoccur for up to 14 days.

  1. Acute - if the duration of fever is less than 7 days
  2. Sub-acute- if the fever lasts up to 14 days
  3. Chronic or persistent- if fever continues for over 14 days

A fever that persists may be serious even if it is a mild fever, as recurrent fever is the indication of more severe infection or health condition.


  • Sweating
  • Chills
  • Headaches
  • Muscle ache
  • Poor appetite
  • Fatigue
  • Weakness
  • Seek immediate medical care if you have a high-grade fever with a temperature of 103F or above continuously for more than 3 days and symptoms include:
  • Pondering headache
  • Dizziness
  • Skin rashes
  • Sensitivity to light
  • Difficult breathing
  • Vomiting
  • Muscle cramps and abdominal pain
  • Dehydration
  • Seizures


Some of the causes of fever in adults include viral infection (flu or a cold), bacterial infection, fungal infection, food poisoning, heat exhaustion, sunburn, inflammation and tumor. Comorbid health conditions like asthma, diabetes, liver disease, kidney disease, rheumatoid arthritis and intake of certain medications for a longer duration may lead to serious febrile illness.


A fever is usually not dangerous on its own, as most fevers go away within hours to days as the body beats an infection. Follow these simple and effective measures to feel better and recover:

  • Drink enough to stay hydrated, like water, juice, clear soup
  • Eat bland and soft diet that are light on the tummy
  • Take enough rest
  • Take a warm sponge bath

Some of the over-the-counter medications may help you relieve fever and other symptoms associated with it like headache, body ache and muscle pain. If the fever is very severe, then the mode of treatment depends on knowing the causative factor behind this and the doctors may prescribe medications like antibiotics, antivirals and antifungals to treat any serious infections