A fever is an increase in your body temperature. Normal body temperature is 98.6°F (37°C). Fever is generally defined as greater than 100.4°F (38°C). What are common causes of a fever? The cause of your fever may not be known. This is called fever of unknown origin. It occurs when you have a fever above 100.9˚F (38.3°C) for 3 weeks or more. Apr 01, 2015 · Fever in adults. Infection is a common cause of fever, but other conditions can also bring the heat. Updated: April 30, 2018. Published: April, 2015. Fever is one of the body's most effective ways of fighting infection. The average body temperature is 98.6° F (37°C). But "normal" body temperature varies from person to person.
Here's what you need to know about fever in adults: What the possible causes are, temperature ranges and when to be concerned, how to make sure the temperature reading is accurate, when you need to see a doctor, stages of fever and how to treat a fever. Adults; Age Temperature What to do; 18 years and up: Up to 102 F (38.9 C) taken orally: Rest and drink plenty of fluids. Medication isn't needed. Call the doctor if the fever is accompanied by a severe headache, stiff neck, shortness of breath, or other unusual signs or symptoms.
Find out more about fever symptoms in adults, when you can use self-care, and what to do if your condition worsens and you need medical help. Find out more about fever symptoms in adults, when you can use self-care, and what to do if your condition worsens and you need medical help. However, older people with a fever are more likely to have a serious bacterial infection than are younger adults with a fever. As in younger adults, the cause is commonly a respiratory or urinary tract infection. Skin and soft-tissue infections are also common causes in older people.