Explain the types of fever
Fever, also known as pyrexia, is a rise in body temperature above the normal range. A person’s normal body temperature can vary, but it is typically around 98.6°F (37°C). Fever is a common response to infection or illness but can also be caused by various other conditions such as inflammation, immune reactions, or certain diseases. There are different types of fever based on their duration, pattern, and cause.
1. **Acute fever:** This type of fever is of short duration, often less than 7 days. It is usually associated with sudden onset and can be a symptom of an acute infection, like the common cold or influenza.
2. **Subacute fever:** This type lasts from 7 days to several weeks and may be indicative of subacute bacterial endocarditis, tuberculosis, or fungal infections.
3. **Chronic fever:** When a fever persists for longer than several weeks, it is considered chronic. Conditions like certain cancers, autoimmune diseases, and chronic infections can be associated with chronic fever.
4. **Intermittent fever:** In this pattern, the fever spikes at regular intervals with periods of normal temperature in between. It is often seen in infections such as malaria or sepsis, or conditions like Pel-Ebstein fever associated with Hodgkin's lymphoma.
5. **Remittent fever:** The temperature fluctuates during a 24-hour period but never returns to normal. Diseases like infective endocarditis or typhoid fever may cause remittent fever.
6. **Continuous fever:** With this type of fever, the body temperature remains above normal throughout the day and does not fluctuate much (less than 1 degree Celsius over 24 hours). Conditions like lobar pneumonia and urinary tract infections may result in continuous fever.
7. **Relapsing fever:** Characterized by episodic fevers interspersed with periods of normal temperatures. Each episode may last from a few days to a week. Diseases that can cause this pattern include rat-bite fever, and recurrent or relapsing infections.
Additionally, fever can be categorized based on its cause:
- **Infectious fever:** Caused by bacterial, viral, parasitic, or fungal infections.
- **Non-infectious fever:** May be due to autoimmune diseases, cancer, drug reactions, or other non-infectious inflammatory processes.
It is also worth noting that the term "fever of unknown origin" (FUO) is used in cases where an extensive workup has failed to reveal the cause of a persistent fever.
The pattern of fever can be a clue to the diagnosis of a specific condition, which is why healthcare providers often inquire about the nature and timing of fever when assessing a patient. Treatment typically includes addressing the underlying cause, as well as using antipyretics (fever-reducing medications) like acetaminophen or ibuprofen to alleviate symptoms and discomfort.