Introduction: Fever
A fever usually means the body has raised its temperature to fight an infection or condition. The most common causes are infectious viruses such as cold or flu. Also possibilities include gastroenteritis, hepatitis, sinusitis, tonsillitis, otitis media, urinary tract infections, measles, roseola, prostratitis, mononucleosis, dental abcess, TB, and drug reactions. The most common causes of fever in children include cold, flu, otitis media, throat infection, UTI, or roseola, but there are numerous other possibilities. Less commonly, fever can be caused by extremely serious conditions such as meningitis, meningococcal disease, and others.
Chronic cases of mild fever can indicate various conditions. Some possibilities are hepatitis, tuberculosis, lymphoma, and reactions to drugs (so-called drug fever). But there are many other possibilities and there is a long list of conditions with fever as a symptom. For comparison, see the list of conditions with cold-like symptoms or flu-like symptoms.