Fever

What are the symptoms of fever?

Medically, a fever is defined as a body temperature of 37.5°C or higher. However, because body temperature varies from person to person, a temperature below 37.4°C can also be considered a fever. In most cases, fever is caused by infection or inflammation, but there may also be complex underlying causes such as collagen disease, cancer, or endocrine abnormalities. Sometimes fever occurs as a normal response when the body is infected with bacteria or a virus and fights the microorganisms that cause the infection, so it is not necessarily bad for the body, and the idea that “all you need to do is lower the fever” is beginning to be reconsidered.

Things to keep in mind when you have a fever

Even if you visit a hospital immediately after the onset of a fever (such as within a day), the cause of the fever is often unknown. If you have a fever but no other symptoms such as loss of consciousness or difficulty breathing, you should consider using over-the-counter antipyretics or general cold medicines, and visiting a general outpatient clinic during the day from the day after symptoms appeared.

Also, since it is easy to become dehydrated when you have a fever, try to drink small amounts of fluids containing electrolytes and carbohydrates, such as sports drinks. If you have symptoms such as drowsiness or difficulty breathing in addition to a fever, you should immediately seek medical attention.

Possible causes of fever

Infectious disease

Most fevers are caused by bacterial or viral infections. If you were feeling fine for a few hours to a few days and then suddenly developed a fever, it is likely an infectious disease. Even if you have an infectious disease, it is most likely a cold or flu, but if you have any of the following symptoms, there is a possibility that another illness is lurking.

• Insect bites or bite marks
• Eating the following foods in the days before the fever started:
  • Raw meat, fish, and spoiled food
• Traveling overseas (especially to countries with poor sanitary conditions, such as Southeast Asia and Africa)
• Sexual intercourse (especially with a new partner)

However, even if you have no idea what the cause may be, it may be an infectious disease, so it is important to tell your doctor as much detail as possible about what happened.

Other diseases

While an infectious disease is often the trigger, if there is no particular cause in mind, the fever may be caused by one of the following illnesses:

• Collagen disease
  • Rheumatoid arthritis
  • Systemic lupus erythematosus
• Cancer and malignant tumors
• Endocrine disorders (hormonal abnormalities)
• Drug side effects
• Functional hyperthermia (a condition in which the body temperature rises due to stress or other psychological factors, even though there is no problem with the organs)

If you have a fever like this, you should see a doctor as it may require specialized treatment.

It is difficult to determine the cause of a fever from symptoms alone, but in any case, as mentioned above, we recommend that you wait for about a day and then consult a medical institution. Please be aware that some medical institutions are currently not able to treat fevers.

High-risk illnesses accompanied by fever

Among the illnesses that cause fever, there are some that are highly urgent and require immediate medical attention, such as acute epiglottitis, meningitis, peritonitis, septic shock, and severe pneumonia.

• Unconscious
• Difficulty breathing
• Severe pain regardless of location
• Within a few hours I was unable to stand up
• Unbearable chills and shivering

If you experience any of the above symptoms, please visit a hospital as soon as possible, including at night or at the emergency room.

summary

• Medically, fever is defined as a body temperature of 37.5°C or higher.
• Infectious diseases are the main cause, but some cases are caused by very serious illnesses.