Last Updated December 20th, 2021
Overview of fevers
Physiological changes may occur within the body due to certain external and internal factors. These changes are manifested through a few inevitable symptoms. A very common symptom that is indicative of existing illnesses within the body is “fever”. The degree of fever may vary according to the severity of the underlying disease. It is a very common occurrence in all age groups, genders, and ethnic groups. Fevers occurring at any point in time should be diagnosed with care. Failure to do so may even lead to fatalities in certain extreme cases. In general, the fever has a direct impact on performance and productivity of school-going children as well as working professionals. This in turn adversely impacts the economy of a nation due to an increased cost of healthcare and hospitalization. Fever is undoubtedly one of the leading causes of increasing global health burden.
What is a fever?
Fever is defined as a mild to the high elevation of the normal human body temperature that is accompanied by certain
The normal human body temperature ranges from 36.5o C to 37oC. The rise of temperature above this value is medically termed as fever.
Fever is basically a manifestation of existing infections or illnesses in the body.
It is actually a sign that the immune system of the body is working perfectly and is capable of fighting infections. Fever may also occur due to various other environmental, physiological and psychological factors.Fever of extremely high intensity needs medical attention and in some cases, hospitalization.
What are the causes of fever?
Multiple factors contribute to fever at any point in time. The commonly studied causes are given below-
- Viral infections caused by the cold and flu virus (Influenza virus) or some other viral pathogens
- Bacterial infections of the lungs, brain, and blood caused by various pathogens (Eg: Staphylococcus)
- Loss of balance between heat loss and heat gain (occurs in old age)
- Rigorous physical exercise (especially during some existing medical condition)
- A side-effect of certain vaccines
- A few over-the-counter drugs (taken for other diseases)
- Abnormal functioning of the thermoregulation center due to drugs or existing illnesses
- Hormonal fluctuations during puberty, pregnancy or menstruation
- Pain in body parts such as head, joints, bones, and muscles
- Emotional stress factors that increase the production of epinephrine and norepinephrine, which in turn impacts the thermoregulation center
- Abnormally increased metabolic activities of different tissues of the body that increases the generation of heat
- Increased basal metabolic rate under certain medical conditions (Eg: Thyroid disorders, wherein increased secretion of thyroxin occurs)
- Elevated temperature of the surroundings (Eg: hot climate, increased room temperature or bathing with very hot water)
What are the different stages of fever?
Fever of any kind usually progresses through the following stages-
- Stage I: It is called the prodrome stage and is characterized by malaise, mild to a moderate headache and extreme fatigue.
- Stage II: This stage is marked by a gradual increase in temperature and occasional chills.
- Stage III: In this stage, the skin feels extremely warm (due to vasodilatation).
- Stage IV: It is also called defervescence and is characterized by sweating.
What are the common symptoms of fever?
Fever is usually manifested through some common symptoms. These are described below
- Feeling of overheated body (hands and feet may feel cold)
- Flushed face
- Extreme fatigue
- Loss of appetite
- Headaches and body pain
- General malaise
- Intermittent chills
- Sweating (indicates gradual remission of fever)
- Nausea and vomiting
- Mood swings and irritability
- Increased heart rate
- Increased respiratory rate
- Coughing (with or without mucus)
- Excessive thirst
- Cramps in hands and legs
- Gastrointestinal disorders
- Urine suppression
- Reddened eyes
- Pain and discomfort in chest and abdomen
- Inflammation, irritation, and pain in nose, eyes, and throat
- Disturbed sleep (especially if fever increases at night)
Different types of fever
Based on the causative agent, fevers may be classified into the following categories-
Bacterial fever: It is triggered by bacterial pathogens. It is characterized by infections of the respiratory or renal tract. The common symptoms of this kind of fever are- a constant cough (productive or non-productive), body pain and chills and problems in urination.
Viral fever: The types of fevers belonging to this category are- Dengue (causes abnormally reduced platelet count), Chikungunya (characterized by joint pain) and Viral Hepatitis (characterized by low-grade fever and yellowish discoloration of the skin).
Parasitic fever: It is associated with the following diseases-
Malaria: Severe chills are observed along with high temperature.
Typhoid: High-grade fever occurs along with an extreme headache and body pains.
Rheumatic fever: High fever occurs along with pain and inflammation in joints
Influenza: Infection of upper respiratory tract occurs in this case.
Meningitis: It is characterized by inflammation of the meninges and may lead to severe ear infections.
Depending on the duration and nature of fever, the following classification is made-
- Continuous fever: In this condition, the body temperature remains more or less constant throughout the day, with occasional fluctuations by one degree. These types of fevers are observed during a few diseases like- Lobular Pneumonia, Brucellosis and Typhoid.
- Intermittent fever: It is characterized by elevated temperature during a particular period of the day and normal temperature during the remaining hours. This is commonly observed in malaria.
- Remittent fever: In this case, body temperature varies in every 24 hours, but never returns to normal temperature.
A few other types of fevers have also been identified. These are-
- Hectic / Septic fever: It is characterized by abnormal fluctuations in body temperature within a time-scale of 24 hours, accompanied by chills and profuse sweating.
- Psychogenic fever: It is characterized by rise of body temperature triggered by emotional stressors (causes rise in levels of epinephrine and norepinephrine)
- Charcot’s (Hepatic) fever: It is caused due to narrowing of the bile duct caused by a tumour or polyps.
- Metal fume fever: This type of fever may arise due to toxicity caused by certain metals (Eg: Inhalation of zinc oxide fumes)
For proper diagnosis of fever, rectal, oral and armpit temperature should be measured accurately. Blood tests may be recommended if the doctor suspects infections or underlying diseases.
Treatment & Prevention
Fever might be an indication of an underlying infection. Thus, most of the time low-grade fevers don’t require any treatment. If the fever is high, then the individual can resort to OTC antipyretics (Over-the-counter fever medications) such as ibuprofen. But long term use of such drugs should be prohibited as they tend to have adverse effect on the liver and the kidneys. Antibiotics may be administered if the cause of the fever is a bacterial infection. Never treat a fever due to viral infection with antibiotics. While in adults fever might be an indicator of something serious, in infants less than 3 months age, a fever requires immediate hospitalization.
There are no definite preventive measures against fever. It is important to build your natural immunity and keep infections at a bay. Keep yourself well-hydrated during the course of a fever. Rest until you fully recover. Never give aspirin to children under the age of 12 years. Avoid caffeinated drinks, alcohol, and tobacco consumption during fever. If the fever becomes too high, use cold water sponges on the forehead to avoid overheating of the body. If fever persists for long and/or the temperate is higher than 104, refer to a doctor immediately.
A few varieties of fevers may be self-limiting in nature, while a few other types may require serious medical intervention. Hence before taking medications for any kind of fever, consultation with one’s physician is necessary. Improper medications or mode of treatments may adversely impact a person’s health and can worsen existing medical conditions.
- Extremely high fever or hyperthermia is a state where the body is unable to regulate the temperature rise. It could be fatal.
- The part of the brain that controls your body temperature is the hypothalamus. One of its most important functions is to keep your body at a consistent 98.6 F.
- If a baby, under the age of 3 months has high body temperature you should immediately go to the doctor, without resorting to self-medication.
- Body temperatures above 108 F can cause brain damage.
- If the fever is caused as a result of the body’s immune system fighting infections, it is not necessarily dangerous. In such cases, the hypothalamus will bring back the temperature to the normal level.
- Fever can have different causes – infection in the body or use of certain medications, also known as drug fever. Sometimes, the cause of the fever remains unknown.
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Dos and Don'ts
- Keep the room cool but not too cold.
- Use a light blanket to cover your body.
- Rest sufficiently and eat a diet which is rich in fresh fruits and vegetables.
- Resort to self-medication for low- grade fevers.
- Consume greasy, sugary, or heavy food.
- Indulge in intense physical exercises or remain outdoors.
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