In a closed community, such as school or workplace, most people develop symptoms within 2 or 3 weeks of the flu's arrival in the place. A person with flu is infectious i.e. he/she can transmit the infection to others a day before the symptoms start and for about five or six days after the start of symptoms.
Flu is caused because of infection with any of the three types of influenza virus namely, type A, B, or C. It spreads by droplets formed when you cough or sneeze (influenza virus is present in small droplets formed when a person coughs or sneezes).
Many people think that flu and common cold are similar, however, in fact, both are different illnesses even though they have many similar symptoms. Common cold is also a viral infection, but it can be caused by several different types of viruses (>200 types), such as rhinovirus, coronavirus, adenovirus, respiratory syncytial virus and parainfluenza virus. The symptoms of flu tend to be more severe and last longer. You may get flu at any time of the year, but it is especially common in winter. The virus may spread by contact as well.
Severity of symptoms in flu may vary from mild to severe. In occasional cases, it may cause death, however, in most cases, it is a self limited disease in which the symptoms improve in a few days without complications.
Some factors that increase the risk of complications in flu are:
Symptoms of flu
Symptoms typically start abruptly 1 - 7 days (usually within 2 - 3 days) after getting infected.
Some common symptoms of flu include:
In most people, the symptoms peak after two to three days (of start of symptoms). Most people recover in a week or so, but you may feel tired for much longer.
Treatment of flu includes symptomatic treatment, such as rest, taking plenty of fluids, fever reducing medicine, such as acetaminophen and tepid sponging to reduce high fever. Antiviral drugs are not prescribed for every one with flu-like symptoms. These are recommended for people, who have severe infection or who are likely to develop complications.