Fever – Causes, Symptoms and Remedies


Many people feel anxious when they suddenly develop a fever and do not know what to do. Here we explain the causes, symptoms, and remedies for a fever, including some professional perspectives.

Causes of Fever

Common Cold

The common cold is an illness caused by a viral infection. Symptoms include a runny nose, sore throat, cough, headache, and fatigue.


Influenza is an illness caused by infection with the influenza virus. Symptoms include fever, sore throat, cough, headache, and tiredness.

Covid-19 infection

New coronavirus (Covid-19) infection is an illness caused by infection with a new type of coronavirus. Symptoms include fever, cough, and tiredness.

Other illnesses

Fever is not only a symptom of the common cold, influenza, and new coronavirus infections. Fever can also be caused by a number of other illnesses, including pneumonia, urinary tract infections, meningitis, and encephalitis.

Symptoms of Fever vary depending on the cause

Common symptoms of fever include:


・Sore throat

・Runny nose
・Muscle pain
・Joint pain


Signs of serious illness when having a Fever

If you have a fever, the following symptoms may be signs of a serious illness:

・Fever that lasts more than 3 days

・High fever(39℃ or higher)

・Severe tiredness or shortness of breath
・Severe sore throat
・Severe headache
・Nausea or vomiting

・Altered mental state or seizures


What to do if you have a fever

If you have a fever, take the following measures:

Take antipyretics

Antipyretics can be taken to reduce fever. Antipyretics are available over the counter.

Drink plenty of fluids

Fluids are easily lost during a fever, so be sure to drink fluids frequently.


If you have a fever, rest to conserve your strength.

Go to a hospital

Get medical attention if you have a fever that lasts more than 3 days, severe tiredness or shortness of breath, sore throat, severe headache, nausea, or vomiting.

If you have a fever, it is important to understand the cause and symptoms and take appropriate steps. Also, because new coronavirus infections are becoming more common, be aware of the possibility of infection and take care of your condition.

At Toranomon Hills Ryu Clinic, our experienced emergency physicians will quickly and carefully evaluate your symptoms.
You can rest assured that we will always make recommendations that are appropriate for your situation and, of course, we will always make sure that you are satisfied with the treatment plan.
Please do not hesitate to contact our clinic for a consultation.