A fever occurs when your hypothalamus—a part of the brain—increases your normal body temperature. This change of your hypothalamus is triggered by special proteins called cytokines that are produced by the infectious organisms
Fevers can be caused by many different conditions. Viral infections, such as the flu (influenza), COVID, RSV or common cold viruses are the most common cause of a fever. Some other causes of fevers include:
-
Food poisoning
-
Bacterial infections such as Staph or Strep
-
Elevated body temperature caused by things other than the action of cytokines in the hypothalamus is caused by hyperthermia. Hyperthermia is usually not caused by infection but by certain medications or medical conditions.
-
Heat exhaustion/heat stroke
-
Certain inflammatory diseases, such as rheumatoid arthritis (RA) and Crohn's disease
-
Medications, including certain antibiotics, SSRI’s used in the treatment of depression and anxiety, and certain hypertension drugs
-
MDMA (ecstasy)