The most frequent causes of fevers are the common cold and stomach flu, but a wide range of conditions can cause fevers, according to WebMD. Some possible contributors are viral or bacterial infections, blood clots, and cancer. Individuals suffering from inflammatory or autoimmune system conditions or hormone disorders can also experience fevers. Certain substances can cause fevers as side effects, including some vaccines, prescription medications and illegal drugs.
Although low-grade fevers are generally relatively harmless in most healthy individuals, they can be serious in newborns, young infants and children with autoimmune disorders. If a child under four months old registers a rectal temperature of 100.4 degrees Fahrenheit or higher, his parent should seek emergency medical attention. Parents should consult a doctor if symptoms persist for more than one day for children under 2 years, or for longer than three days for older children. Additional symptoms such as fatigue, decreased appetite, nausea, dizziness and diarrhea can indicate more serious conditions, and individuals should seek medical attention, explains WebMD.
Doctors attempt to diagnose and treat the underlying causes of fevers, and treatments vary based on condition, notes WebMD. Individuals can manage the symptoms of fevers to alleviate discomfort with over-the-counter medications such as aspirin, ibuprofen, naproxen and acetaminophen.