What are the Causes of Fever


The mechanism of fever development includes the setting of our body’s thermoregulation controlled by hypothalamus to higher level. It makes one feel colder, and thus both voluntarily and involuntarily we try to keep ourselves warm. That is how the fever develops. Fever is actually a protective method employed by our body to fight against problems like infections.

Let us take a look at some of the conditions leading to fever.

  1. Amongst all the causes of fever infection holds the first place. Nearly all kinds of infections cause fever. Some of these infections where fever is prominent are as follows:
    • Respiratory infections like common cold, flu, pneumonia, bronchitis, mononucleosis, sinusitis, sore throat, tuberculosis
    • Bone infection like osteomyelitis
    • Skin infections like cellulitis
    • Abdominal infections like viral gastroenteritis, bacterial gastroenteritis and appendicitis
    • Meningitis
    • Infections of the urinary tract
    • Post immunization in children (low-grade fever generally)
  2. Many a time fever might be the first presentation of a cancer especially in leukemia, non-Hodgkin lymphoma and Hodgkin lymphoma.
  3. Children may suffer from low-grade fever during teething, though the temperature seldom reaches 100°F.
  4. Various autoimmune disorders and inflammatory disorders may represent as fever too. Some of them are as follows:
    • Connective tissues disorders like systemic lupus erythematosus or rheumatoid arthritis
    • Crohn’s disease or Ulcerative colitis
    • Periarteritis nodosa
    • Vasculitis
  5. Other causes of fever are:
    • Thrombophlebitis
    • Medications like antihistamines, antibiotics, antihypertensive or antiepileptic drugs
    • Extreme sunburn or heat exhaustion

Many a times a proper cause of fever cannot be identified even after extensive diagnostic methods. When the cause is not identified for a fever (over 101°F or more lasting for 3 weeks or more) even after extensive evaluation the it is termed as pyrexia or fever of unknown origin (PUO or FUO).