Fever and Flu

I noticed flu medicine if salable nowadays. Now wonder because the weather is so unpredictable. In fact, we were just hit by a typhoon so it was raining the past few days. While a week prior to this, the sun smiles brightly so i don't know what's really the exact weather on this month. I heard a dry spell will hit us and i think it was true due to the evidence of crack lands in some places.

Anyway, going back to flu season. I had a quick research and here's what i've got:

Influenza, commonly known as the 'flu' , is an infectious disease of birds and mammals caused by RNA viruses of the family Orthomyxoviridae, the influenza viruses. The most common symptoms are chills, fever, sore throat, muscle pains, headache (often severe), coughing, weakness/fatigue and general discomfort. Although it is often confused with other influenza-like illnesses, especially the common cold, influenza is a more severe disease caused by a different type of virus.[2] Influenza may produce nausea and vomiting, particularly in children,[1] but these symptoms are more common in the unrelated gastroenteritis, which is sometimes inaccurately referred to as "stomach flu" or "24-hour flu".[3] Flu can occasionally lead to pneumonia, either direct viral pneumonia or secondary bacterial pneumonia, even for persons who are usually very healthy.

In particular it is a warning sign if a child (or presumably an adult) seems to be getting better and then relapses with a high fever as this relapse may be bacterial pneumonia.[7] Another warning sign is if the person starts to have trouble breathing.