(CNN) - It's the season for sneezing and coughing but when it comes to telling whether you have the flu or just a common cold, it's sometimes almost impossible.
The flu and the common cold affect the respiratory tract but they are caused by different viruses. The flu is caused by a stronger virus that, if not taken care of, can develop other complications like pneumonia, bacterial infections, or require hospitalizations.
Symptoms of the flu are usually worse than those of the common cold. They include fever, body aches, extreme fatigue and an intense dry cough. Common colds usually just come with a lot of congestion, including runny or stuffy noses.
There are tests that can be done in the first few days of an illness if you need to make sure you or a loved one don't have the flu. Little ones, people with immune problems and the elderly are susceptible to flu complications. If you aren't sure, call your doctor.
The best way to avoid the flu is to get a flu shot -- and there's still time. The flu season usually lasts through late February or early March.