The flu is a contagious disease that effects millions of people all around the world. It's caused by an airborne virus and can be spread by sneezing, coughing or just by opening the mouth to speak. Typical symptoms of the flu are sudden and can last up to 5 days. The elderly, very young or those with chronic illnesses such as asthma or heart disease are the most susceptible to the flu but anyone can get the flu. See your doctor if you experience the flu symptoms listed in the article below, especially during flu season.