Cold, Flu, & Cough Health Center

Top 10 Questions About the Flu

Influenza, or flu, is a virus that targets the respiratory system. Find answers to the 10 most common questions about the flu.

1. What is the difference between a cold and the flu?

The flu and the common cold are both respiratory illnesses, but they are caused by different viruses. Influenza or "the flu" develops when a flu virus infects your respiratory system, including your nose, throat, bronchial tubes, and possibly the lungs. A cold virus usually infects only your upper respiratory tract: your nose and throat.

The flu usually causes more severe illness than the common cold. Flu can bring on fever, body aches, and exhaustion, symptoms that are rarely caused by simple colds.

2. What are flu symptoms and when is a person contagious?

Primary symptoms of flu are fever, fatigue, aches and pains, chills, and cough. The cough is a bronchial tube irritation and is usually not productive -- you're not coughing up gunk. The flu is usually at its worst for three to four days. The cough may linger longer. Recovery can take seven to 10 days. You may have lingering fatigue for several weeks.

There's one catch with these viruses. About 24 to 72 hours after you're infected, you become contagious. Yet you may not have symptoms, so you don't know you're sick. You feel completely healthy, and go about your daily affairs -- spreading the virus wherever you go.

Stay at home while you've got the flu, and for at least 24 hours after you get over your symptoms. Once you start feeling symptoms, you've already exposed co-workers to the virus -- and you're still contagious. Also, you will recover quicker if you get some rest.

3. What's the best treatment for flu?

There's no single "best" treatment for flu, but there are many ways you can ease symptoms.

Prescription flu drugs can shorten the time you feel sick if taken when your first symptoms appear. They work best when taken within 48 hours of symptoms, but they can also prevent severe disease if taken more than 48 hours after the first symptoms. Over-the-counter cold and flu medicines can offer some relief from fever, aches, stuffy nose, and cough. They don't "cure" the flu, but may help keep you more comfortable.

What can help? Decongestants can help you breathe by shrinking swollen mucous membranes in your nose. Saline nasal sprays can also help open breathing passages. Cough preparations, along with water and fruit juices, can help soothe a cough.

Don’t use over-the-counter cough and cold medicines in children under 4. If your child is between 4 and 6, ask your doctor before giving medicine. It’s safe to use these medicines to help relieve symptoms in kids 6 and older. Never give medicines with aspirin to young adults and children due to the risk of Reye’s syndrome.

It's very important to drink a lot of fluids to keep your body hydrated. This helps loosen mucus. Limit drinks like coffee, tea, and colas with caffeine. They rob your system of fluids. As for eating, follow your appetite. If you're not really hungry, try eating simple foods like white rice or broth.