Fever is a general symptom when the human body temperature rises above standard range (36–37° Celsius or 98–100° Fahrenheit). It is also known as pyrexia or controlled hyperthermia. The condition signifies that something is wrong with the vital parameters of the body. It may occur due to infections like influenza, malaria, and common cold, trauma or injury, vaccination, cancer, hyperthyroidism, or side-effects of medicines.

Fever may cause associated discomforts like shivering, lethargy, lack of appetite, and sleepiness. However, it is a prevalent physical condition and every individual experiences it at certain stages in their life. The immune system nullifies an infection through this symptom. As long as the body temperature does not rise beyond 100.4° Fahrenheit, there is nothing to worry about in fever.

Different types of fever
There are different types of fever based on body temperature at different times of the day.

Intermittent fever
In intermittent fever, body temperature remains around 37° Celsius during the day, however, at night it increases above the standard range. Individuals show this type of pyrexia during bacterial or parasitic infection like septicemia and malaria. It is again subdivided into three sub-categories:

• Quotidian fever (pyrexia occurs within 24 hours, and is seen in Plasmodium knowlesi infection)
• Tertian fever (pyrexia occurs within 48 hours, and is noticed in Plasmodium vivax and Plasmodium ovale infection)
• Quartan fever (pyrexia occurs within 72 hours, and is seen in Plasmodium malaria infection).

Continuous fever
In the case of continuous fever, body temperature remains high throughout the day. Individuals do not experience fluctuations of more than 1 degree Celsius in their temperature within 24 hours. It is common during infections like salmonella typhoid, urinary tract infection, lobar pneumonia, scarlet fever, or meningitis.

Remittent fever
In remittent fever, body temperature remains above standard range throughout the day, and diurnal variation is more than 1 degree Celsius. It is the main difference between remittent fever and continuous fever. It may occur in ineffective endocarditis, typhoid, and brucellosis. Physicians usually prescribe antipyretics to manage the condition.

Pel-Ebstein fever
Pel-Ebstein fever is common in Hodgkin’s lymphoma where individuals experience cyclic increase and a decrease in body temperature in about seven days to a fortnight. In this condition, the white blood cells count gets affected and body temperature increases due to the action of Epstein-Barr virus.

Neutropenic fever
Neutropenic fever is also known as febrile neutropenia, and it commonly occurs due as a side-effect of chemotherapy or dialysis in patients. Individuals undergoing organ transplantation may also experience this type of fever.

Rheumatic fever
Rheumatic fever usually occurs in children from five to fifteen years in the sub-Saharan region, Central Asia, New Zealand, and Australia. Group A Streptococcus is the primary causal agent of this type of fever. Common symptoms include a sore throat, high body temperature above 101°F (38.3°C), swollen and tender joints in knees, ankles, or elbow, red rashes on the skin, chest pain, and thick bloody discharge from the nose.

The above are the different types of fever that a person might suffer from. So, if your body temperature rises above 100.4° Fahrenheit, ensure to consult a doctor immediately.