Colds and flu shares many of the same symptoms. So what's the difference? A cold is usually milder than the flu, and the flu is more likely to lead to pneumonia. Chances are you've been dealing with these common illnesses throughout your life. But as you get older, your body has a harder time fighting off infection. Once you have a cold or influenza, there is a greater chance that it will develop into a more serious illness. Also, if you have a chronic illness such as emphysema or diabetes, influenza can be very serious or even life-threatening. For these reasons, it's important to recognize influenza-related symptoms and to learn when it's time to see the doctor. By doing so, you can prevent a cold or influenza from turning into a more serious illness. According to the National Institute of Allergy and Infectious Diseases, the following are symptoms of both colds and flu: Sore throat; this is much more common with the flu Runny nose and sneezing, although these are rare with influenza Headache; there is sometimes a headache with a cold but always a headache with flu Overall sick feeling; this is called malaise and is more profound with influenza than with a cold Low-grade fever with a cold; high fever with influenza Muscle aches; these are more common with influenza than with a cold The flu is more likely to lead to pneumonia. For this reason, you need to know if you have a cold or the flu. A cold usually does not cause fever above 101 degrees F, while the flu can. Also, a stuffy nose is probably a sign of a cold, rather than the flu. Overall, cold symptoms are milder and do not cause extreme exhaustion like the flu can. Colds may occur any time of the year, although they are more common in the fall, when school begins; in the winter; and in the early spring. In the United States, influenza is usually seen from about October through April, and the rate of infection can peak in April or as late as May. Because colds and influenza flu are caused by viruses, there is no cure. The course and severity of influenza, however, can be moderated by antiviral medications. If you are young and healthy, you don't need anything further than to let a cold or flu run its course. Older adults, particularly those with existing chronic health problems, should seek care for influenza and may do better with antiviral medication. It's important to rest and drink plenty of fluids. Talk with your doctor about over-the-counter medicines that may help ease your symptoms. The following symptoms may indicate a problem more serious than a common cold or influenza: chest pain, wheezing, high fever, frequent colds, shortness of breath that comes with little or no exertion, phlegm or mucus produced for two or more weeks, or a cough that lasts two weeks or produces blood. See your doctor right away if you have any of these symptoms or if any symptoms last longer than usual for a common cold or the flu. The earlier you catch problems, the more easily they can be treated.