Fever Overview

Fever

Fever is a common sign and symptom observed in a variety of clinical settings.¹

The normal body temperature is about 36.5°C to 38°C, with the typical temperature at 37°C. In a healthy afebrile person, the hypothalamic thermoregulatory centre of the brain regulates body temperature by balancing the heat produced during metabolism and that released through respiration and evaporation.¹ However, when this balance is offset due to different reasons, fever sets in.

One common symptom in a variety of conditions²

Fever is considered a natural reaction when the body is ill and is one of the oldest indications of disease. It often occurs due to infection, inflammation and trauma to the body. As it is a response of the body involving multi-systemic mechanisms that occur when the body is ill, fever is considered a significant contributor to the pathogenesis, clinical presentation and outcome of many illnesses and disease.

Fevers can be classified into acute, subacute and chronic.

Fever	Duration
Acute	< 7 days and characteristic of most infectious diseases.
Subacute	Not more than 2 weeks and seen in certain infections such as typhoid fever.
Chronic	Also known as persistent fever lasting for > 2 weeks and typical in chronic bacterial infections such as tuberculosis, cancers and viral infections like HIV.

Fevers can also have specific patterns depending on its cause and this together with other signs and symptoms are used to diagnose the underlying disease, infection or condition.