Fever in Adults

A fever is a temporary increase in body temperature, typically above 98.6°F (37°C). It is a common symptom that can occur in response to various conditions, including infections, inflammatory diseases, and other medical disorders.

Causes of Fever in Adults

  • Infections: bacterial, viral, fungal, or parasitic infections, such as pneumonia, influenza, urinary tract infections, or sepsis
  • Inflammatory conditions: rheumatoid arthritis, lupus, or other autoimmune disorders
  • Cancer: certain types of cancer, such as lymphoma or leukemia, can cause fever
  • Medications: some medications, including antibiotics, blood pressure medications, and anti-seizure medications, can cause fever as a side effect
  • Vaccinations: some vaccinations, such as the flu vaccine, can cause a low-grade fever
  • Environmental factors: exposure to extreme temperatures, heatstroke, or dehydration

Symptoms of Fever in Adults

  • Elevated body temperature, usually above 100.4°F (38°C)
  • Chills or sweating
  • Headache or muscle aches
  • Fatigue or weakness
  • Loss of appetite
  • Nausea or vomiting
  • Dehydration

Diagnosis of Fever in Adults

To diagnose the cause of a fever, a healthcare provider will typically perform a physical examination and take a medical history. They may also order diagnostic tests, such as:

  • Blood tests: to check for signs of infection or inflammation
  • Imaging studies: X-rays, CT scans, or MRI scans to evaluate the lungs, abdomen, or other organs
  • Urine tests: to check for urinary tract infections
  • Stool tests: to check for gastrointestinal infections

Treatment of Fever in Adults

The treatment of fever depends on the underlying cause. In some cases, the fever may resolve on its own without treatment. However, if the fever is high or persistent, treatment may include:

  • Medications: antipyretics, such as acetaminophen or ibuprofen, to reduce fever
  • Antibiotics: to treat bacterial infections
  • Antiviral medications: to treat viral infections, such as influenza
  • Supportive care: rest, hydration, and nutrition to help manage symptoms

Complications of Fever in Adults

In some cases, fever can lead to complications, such as:

  • Dehydration
  • Seizures
  • Brain damage
  • Organ failure
  • Septic shock

Prevention of Fever in Adults

To prevent fever, it is essential to:

  • Practice good hygiene: wash hands frequently and avoid close contact with people who are sick
  • Stay up-to-date on vaccinations: get vaccinated against flu, pneumonia, and other infections
  • Avoid sharing personal items: do not share utensils, glasses, or other personal items to prevent the spread of infection
  • Get enough rest: aim for 7-8 hours of sleep per night to help keep the immune system strong

Article last updated on: 15th June 2025.
If you have any feedback, please get in touch.

Diagnosis Pad
Medical AI Assistant with Differentials, Guidance, Transcriptions, Notes, Medical Encyclopedia and Explainable AI.


Available for iOS, macOS and Android.

Medical Disclaimer

The information provided is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read on this site. We we do not guarantee, and assume no legal liability or responsibility for the accuracy, currency, or completeness of the information provided.