What Is the Difference Between the Flu & a Virus?

Both the flu and the common cold are caused by viruses. However, the virus that causes the flu usual causes more severe symptoms than the virus that causes the common cold.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Symptoms of the Common Cold

The common cold is caused by a virus that invades the upper respiratory system. Cold symptoms usually appear slowly and can include a runny nose, sore throat, sneezing, headache and general malaise. In some cases, the cold virus can cause a mild fever or muscle aches.

Symptos of the Flu

Symptoms of the flu usually appear suddenly and are similar to those of the common cold. However, the flu is usually characterized by excessive tiredness, loss of appetite, chills and sweats, nausea and more severe muscle aches and fever.


Many people perceive the flu and a cold to be the same thing 1. However, the flu is much more serious than a cold. If you have a cold virus, you may not feel 100 percent, but you'll probably be able to continue with your normal activities. If you have the flu, you probably won't want to get out of bed, much less carry on with your normal daily activities.

Side-Effects of the Flu and the Common Cold

The common cold rarely leads to serious side-effects. However, if the symptoms of the flu aren't treated or the patient doesn't get adequate rest, the flu can turn into pneumonia, which can be deadly, especially for elderly individuals. Thousands of people in the United States die every year from the flu.


In order to prevent or decrease your chances of contracting the common cold and flu, it is important to wash your hands frequently to prevent germs from spreading.

More than 200 viruses can cause a common cold, but only a few cause the flu. For that reason, a yearly vaccine exists for the flu but not the common cold.

The most effective way to prevent the flu is to get vaccinated against the flu every fall.

If you contract the flu and experience severe symptoms, your doctor can prescribe an antiviral, such as Tamiflu, for you. Even though antivirals don't cure the flu, they can shorten the duration and severity of the illness.


The flu can be particularly dangerous for older people or those with a compromised immune system. If you are older than 60 or suffer from an immune-deficiency disorder, it is important to contact your doctor and monitor your symptoms closely to make sure severe side-effects don't occur.