Fever in Adults: Causes

How does fever occur?

Fever occurs when the hypothalamus resets the normal temperature point to a higher level. Although the body is still working to balance the heat produced with the heat which it releases, since the set-point is now higher, the body temperature rises.

The increase in body temperature occurs for various reasons, such as release of certain chemicals called cytokines in response to invading microorganisms, cancer cells, or any other foreign matter. It is also in response to the body producing white blood cells and antibodies to protect it from the invading foreign matter.

Causes of fever

Infectious causes of fever
Any form of infection can cause the body to respond with a fever. These include viral and bacterial infections. Some examples are:

Viral infections:

Common cold

Influenza

Meningitis

Dengue fever

Gastroenteritis

Bacterial infections:

Dysentery

Bacterial pneumonia

Tuberculosis

Skin infections

Urinary tract infections

Otitis media (ear infections)

Eye infections
Noninfectious causes of fever
Although it is more common for a person to develop fever because of an infection, there are noninfectious causes of fever. These include:

Autoimmune diseases

Systemic lupus erythematosus (SLE)

Rheumatoid arthritis

Cancers

Leukemias

Lymphomas

Drug induced

Sulfa drugs

Some antiepileptic medications

Antiretroviral medicines (for treatment of HIV)

Some antiarrhythmic medications (eg, amiodarone)

Crystal-induced arthropathies

Gout (accumulation of uric acid in the joints)

Thromboembolism

Deep vein thrombosis

Abdominal conditions

Acute pancreatitis

Central nervous system conditions

Stroke (hemorrhagic and ischemic)