Cold vs. Flu: Tips to Know the Difference and Stay Well

Timothy J. Linker, MD, is a family and sports medicine specialist at Atrium Medical Center in Middletown.

Q. What’s the difference between the common cold and the flu? How can you prevent illness? Who should get a flu shot — and when?

A. The flu and the common cold are both respiratory illnesses caused by different viruses. Because they have similar flu-like symptoms, it can be difficult to tell the difference between them based on symptoms alone.

A cold is milder than the flu. While cold symptoms can make you feel bad for a few days, flu symptoms can make you feel quite ill for a few days to weeks. With a cold, you may be considering whether you’re well enough to go to work or school. With flu, there’s usually no question because you’re down and out in bed.

Cold symptoms often begin with a sore throat, which usually goes away after a day or two. Nasal symptoms, runny nose and congestion follow, along with a cough by the fourth and fifth days. Fever is uncommon in adults, but a slight fever is possible. Children are more likely to have a fever with a cold. Several hundred viruses may cause your cold symptoms.

Initially, the flu may seem like a common cold with a runny nose, sneezing and sore throat. But colds usually develop slowly, whereas the flu tends to come on suddenly. Symptoms of flu include sore throat, fever, headache, muscle aches and soreness, extreme tiredness, congestion and dry cough.

Most flu symptoms gradually improve over two to five days, but it's not uncommon to feel run down for a week or more. A common complication of the flu is pneumonia, particularly in the young, elderly, or people with lung or heart problems. If you notice shortness of breath, let your doctor know. Another common sign of pneumonia is a fever that comes back after having been gone for a day or two.

The flu is highly contagious. The influenza virus usually enters the body through mucus membranes in the mouth, nose or eyes. When a person with the flu coughs or sneezes, the virus becomes airborne and can be inhaled by anyone nearby. You can also get the flu if you’ve touched a contaminated surface like a telephone or a doorknob and then touch your nose or mouth. Of course, the risk of infection is greater in highly populated areas like schools, buses, and crowded settings.

Older adults, young children and people with specific health conditions are at higher risk for serious flu complications. On average annually in the US, 5 to 20 percent of the population gets the flu; over 200,000 people are hospitalized from flu complications; and about 23,600 people die from flu-related causes.

The most important way to prevent colds and flu is frequent hand washing. Rubbing the hands with warm soapy water for at least 20 seconds helps to slough germs off the skin. When you sneeze or cough, cover your nose and mouth with a tissue (not your hands) and throw the tissue away immediately. Cough into your sleeve if you don’t have a tissue handy.

The best way to prevent seasonal influenza is to get a flu vaccination each year. The Centers for Disease Control and Prevention now recommend annual flu vaccination for all Americans over the age of 6 months. Scientists make a different flu vaccine every year because the strains of influenza viruses change from year to year. The vaccine is typically available as an injection or as a nasal spray.

Seasonal flu activity generally peaks between late December and early March. Within two weeks of getting a flu vaccine, antibodies develop in your body and provide protection against flu. Children receiving the vaccine for the first time need two doses delivered one month apart.

Antiviral medicine may help prevent flu if you have been exposed to someone with flu symptoms. These prescription medications actively attack the flu virus and stop it from spreading to the rest of your body. To be effective, antiviral medications must be taken within the first 48 hours of onset of flu symptoms.

During this busy time of year, do all that you can to protect yourself and your family from colds and flu. If you do get sick, talk with your doctor about the best way to treat your symptoms.

This information is for educational purposes only. Please talk to your physician for advice in all matters related to your health.