What is a Fever ?
A fever is typically a sign that something unusual symptoms caused by a variety of illnesses happens in your body. Minor illnesses may create a high fever, whereas major illnesses may cause a mild fever.
In normal adults, the average oral temperature is 37°C (98.6°F). Fever (also termed pyrexia) is elevated body temperature >100° F orally or 100.8° F rectally (> 37.8° C orally or > 38.2° C
rectally) or an elevation above a person’s known normal daily value.
Fever (Pyrexia) Hyperthermia Fever is “an elevation of body temperature that exceeds the normal daily variation and occurs in conjunction with an increase in the hypothalamic set point.” In other words, in a fever, the body is trying to raise the temperature above normal, as a response to pyrogens (like bacterial antigens).
The condition is defined as “an unchanged normothermic) setting of the thermoregulatory center in conjunction with an uncontrolled increase in body temperature that exceeds the body’s ability to lose heat.” Causes of hyperthermia include heat stroke, drug-induced hyperthermia, and malignant hyperthermia.
What Causes Fever?
Fever usually occurs in response to an infection as with the flu virus or inflammation that occurs with tissue injury or disease. However, many other causes of fever are possible :
- Infections of the ear, lung, skin, throat, bladder, or kidney
- Heat exhaustion
- Viral infections such as the flu or COVID-19
- Conditions that cause inflammation, such as rheumatoid arthritis
- Injuries or abnormalities to the brain,
- Side effects of medications
- Vaccines and immunizations
- Cancer
- Hormone disorders such as hyperthyroidism
- Teething in babies can result in a mild, low-grade fever (not exceeding 101 degrees).
Fever occurs when the body’s immune response is triggered by pyrogens (fever-producing substances). Pyrogens that occur outside the body include the following:
- Viruses
- Bacteria
- Fungi
- Drugs
- Toxins
Infectious causes: Virtually all infectious illnesses can cause fever. But overall, the most likely causes are Upper and lower respiratory tract infections, Gastro Intestinal infections, Urinary Tract infections, Skin infections. Most acute respiratory tract and GI infections are viral.
Types Of Fever :
- Low-grade fevers range from about 100 F-101 F
- High-grade fevers range from about 103 F-104 F.
- Dangerous temperatures are high-grade fevers that range from over 104 F-107 F or higher.
This is a medical emergency because temperature approaches the upper limit compatible with human life.
Common manifestations of diseases depending on the type of fever:
Malaria : Infections with P. vivax, P. ovale, and P. malariae can cause a cyclical pattern of chills, rigidity, and high fever. P. falciparum is more likely to cause fever with intermittent increases.
In malaria the fever is of shorter duration. The symptoms include chills, anemia, joint pain, vomiting, convulsions and sweating.
Symptoms of malaria typically occurs in three stages namely, cold stage, hot stage and sweating stage.
1. The “cold” or “chilling” stage lasting 15 minutes to several hours during which the patient feels cold and has shaking chills.
2. The second “hot” stage lasts several hours and coincides with red blood cell rupture and merozoite release. During the second stage temperatures rise to 40°C (104°F) or higher. There is minimal sweating and the patient is at risk of febrile seizures. Clinical signs and symptoms include tachycardia, hypotension, cough, headache, backache, nausea, abdominal pain, vomiting,
diarrhea, and altered consciousness.
3. Within 2-6 hours, the patient enters the third “sweating” stage with generalized sweating, resolution of fever, and marked exhaustion, usually giving way to sleep.
Typhoid (Enteric fever) :
Temperature remains above normal throughout the day and does not fluctuate more than 1 °C in 24 hours. Typhoid fever begins 7-14 days after ingestion of Salmonella typhi bacteria. The fever pattern is stepwise, characterized by a rising temperature
over the course of each day that drops by the subsequent morning. The peaks and troughs rise progressively over time. Fever accompanied with
- Abdominal pain,
- Headache,
- Muscle pains,
- Cough,
- Weakness,
- Diarrhea or constipation,
- Rash (red-spots)
- altered sensorium.
It starts with sudden onset of fever that last for long duration (about seven days). This fever can go up to 39.5-41.4°C (103.1-106.52°F) and is accompanied by headaches and muscle or bone pain. The fever may vanish and then reoccur along with skin rashes. Other symptoms of dengue include
- Nausea,
- Vomiting
- Loss of appetite
- Pain in eyes
- Rashes on upper and lower limbs.
Treatment : The treatment of a fever depends on its cause.
- In most cases, except in hyperthermia, acetaminophen or ibuprofen can be given to lower the temperature. The daily dose of acetaminophen should not exceed 4 gm to avoid toxicity; patients should be warned not to simultaneously take nonprescription cold or flu remedies that contain acetaminophen
- NSAIDs (such as aspirin and naproxen) are also efficient antipyretics. Salicylates should not be used to treat fever in children with viral infections, as they have been linked to Reye syndrome.
- Fluids may be given by mouth or IV to prevent dehydration, if necessary.
Most fevers will go away in a few days with the appropriate treatment. It is important for the patient to follow up with the health care professional to be sure the cause of the fever is treated correctly.
If symptoms increase, the fever persists for more than three days despite treatment, or the fever lasts more than a week without treatment, visit a doctor right away. Follow-up is especially critical for patients who have fevers caused by cancer, drug-induced fevers, infectious reasons, Fever of Unknown Origin, or hormone abnormalities, as these people may experience relapses and require many treatments. In some circumstances, hospitalization may be necessary.
Fever Treatment at Home :
- Drink plenty of fluids : Fever can induce fluid loss and dehydration, so stay hydrated with water, juices, or electrolyte-containing beverages. Keep the patient well-hydrated, as dehydration caused by a mild fever might be more dangerous than the fever itself.
- Rest: It is necessary for recovery, and activity can raise body temperature.
- Stay cool : Dress in light & loose clothing
- Keep the room temperature cool and sleep with
only a sheet or light blanket. - For high temps, a 5-10 minute soak or sponge bath might be refreshing. If you shiver when taking a bath, stop and dry off.
*Shivering increases the body’s internal temperature because shaking muscles produce heat. - Tepid water sponging may be useful to reduce body temperature. Studies show no additional benefit from sponging after antipyretic administration. If used, administer antipyretics 30 minutes before sponging to reduce hypothalamic set point. Tepid sponging, if performed, should be done with water
only. Do not cold-sponge a person with fever.
Prevention of Fever in Adults:
Most fevers come from an infection. Individuals can help to prevent the spread of infection and thus prevent fever.
- Wash the hands frequently and avoid touching the face or mouth as much as possible.
- Keep the home and work environment clean.
- Avoid direct contact with sick people.
- Do not share cups or utensils, towels or clothing, especially if they are not clean.
- Wear appropriate protective clothing and equipment when working with animals.
- Stay well hydrated
Stay healthy, stay safe