Fever Quiz

Understanding Fever (Pyrexia)

Fever, also known as pyrexia, is a common medical sign characterized by an elevation of body temperature above the normal range. It is a key part of the body’s immune response, often indicating that a battle is being waged against an infection. This guide explores the mechanisms, causes, and management of fever.

What Defines a Fever?

A body temperature is generally considered a fever when it reaches 100.4°F (38°C) or higher. However, the exact threshold can vary slightly based on the method of measurement (oral, rectal, axillary, or tympanic) and the individual’s age.

• Oral (mouth): 100°F (37.8°C) or higher
• Rectal (bottom): 100.4°F (38°C) or higher (most accurate for infants)
• Axillary (armpit): 99°F (37.2°C) or higher

The Physiology of Fever

Fever is triggered by substances called pyrogens. These can be exogenous (from outside the body, like bacteria or viruses) or endogenous (produced inside the body, like cytokines). These pyrogens cause the hypothalamus, the body’s thermostat, to reset the normal body temperature set-point to a higher level. The body then works to raise its temperature to this new set-point through mechanisms like shivering and vasoconstriction (narrowing of blood vessels).

Common Causes of Fever

Fever is a symptom, not an illness itself. It is most commonly caused by infections but can have other non-infectious causes.

• Infections: Viral (e.g., influenza, common cold), bacterial (e.g., strep throat, pneumonia), and fungal infections are the primary culprits.
• Inflammatory Conditions: Autoimmune diseases like rheumatoid arthritis and lupus can cause chronic low-grade fevers.
• Medications: Certain drugs, including some antibiotics and antihistamines, can induce a fever (drug fever).
• Heat Exhaustion: Prolonged exposure to high temperatures can overwhelm the body’s ability to regulate its temperature.
• Vaccinations: A low-grade fever after a vaccination is a normal sign that the immune system is responding.

Febrile Seizures

A febrile seizure is a convulsion in a child that can be caused by a spike in body temperature. While frightening for parents, simple febrile seizures are generally harmless and do not cause long-term brain damage. They typically occur in children between 6 months and 5 years of age.

Managing a Fever

The primary goal of treating a fever is to improve comfort, not necessarily to normalize the body temperature, as fever itself is a beneficial immune response. Key management strategies include:

• Hydration: Drinking plenty of fluids like water, juice, or broth is crucial to prevent dehydration.
– Rest: Allowing the body to rest helps it fight the underlying illness. – Medication: Over-the-counter fever reducers (antipyretics) like acetaminophen or ibuprofen can be used to lower temperature and relieve discomfort. Aspirin should not be given to children or teenagers due to the risk of Reye’s syndrome. – Comfort Measures: A lukewarm bath and light clothing can help make the person more comfortable.

When to See a Doctor

While most fevers resolve on their own, certain situations warrant medical evaluation. Seek medical advice if a fever is accompanied by symptoms like a severe headache, stiff neck, rash, difficulty breathing, or confusion. For children, specific guidelines based on age and temperature should be followed.

This information is for educational purposes. Always consult with a healthcare professional for diagnosis and treatment of medical conditions.