Although viral infections typically cause fevers that last two to three days, some fevers can last for as long as two weeks, according to AboutKidsHealth. Fevers caused by bacterial infections can continue indefinitely until the infection receives proper treatment with antibiotics.
A fever is not itself a sign of illness or disease, explains AboutKidsHealth. A fever occurs as a reaction when the body's immune system fights against infections. A variety of infections can cause fevers, and diagnosis depends on other accompanying symptoms. To manage a fever, patients should dress lightly, drink plenty of extra fluids, and take medication such as acetaminophen or ibuprofen.