Influenza: What You Need to Know

by Melissa Chichester

Every year, millions of people are affected by influenza, or “the flu.” This highly contagious virus impacts the respiratory system. Some populations are more vulnerable than others when they come into contact with the flu. In addition, it can be confusing to know the difference between the flu and the common cold. Let’s take a look at some of the most common questions people have about the flu, and how to spot the difference. 

What is the flu? 

The flu is a common virus that spreads easily and irritates the nose, throat, and lungs. It occurs in two types: influenza A and influenza B. Most people associate the flu with stomach discomfort and vomiting, but these two illnesses are not the same thing. 

When is “flu season?”

Seasonal influenza, better known as “flu season,” typically hits its peak in the United States December through February. Flu activity tends to rise beginning in October. Although this is a common trend, it is important to note that the flu can occur all year long. For detailed, up-to-date activity on flu viruses, visit FluView by the Centers for Disease Control. FluView provides weekly surveillance on the flu, including information about geographic locations. 

How does the flu spread?

The flu is highly contagious. The flu virus spreads by traveling in droplets through the air. These droplets are produced when people with the virus cough, sneeze, laugh, and even talk. When another person inhales these droplets, they can become infected. Talking on the phone, touching door handles, and sharing computers are all ways the flu can spread. The flu can survive in these droplets for several hours. 

What is the difference between a cold and the flu?

It isn’t always easy to know if it is a cold or the flu, but there are some key differences. The flu comes on more abruptly and strongly than the common cold, whereas a cold tends to come on more gradually. One of the biggest identifiers of the flu is that it is usually accompanied by a fever (but not always). 

What are the signs and symptoms of the flu? 

Common signs of the flu include:

  • Fatigue and muscle aches
  • Fever above 100 degrees F (38 C)
  • Chills 
  • Headache
  • Chest discomfort 
  • Sweating 
  • Runny nose 
  • Dry coughing 

These symptoms can be signs of other conditions. It is always important to discuss symptoms with a healthcare practitioner. 

What populations are at high risk of getting the flu?

Some populations are more vulnerable to contracting the flu, including: 

  • Adults older than age 65
  • Children younger than 5 
  • Infants younger than 12 months
  • Pregnant women
  • People living in long-term care facilities
  • People with chronic diseases 
  • People with weakened immune systems 

How long does the flu last?

An average bout with the flu may last from one to two weeks. 

Can I get the flu more than one time? 


Yes. Flu virus strains change; therefore, you can get it again.

How can I avoid the flu if I know someone is contagious?

Finally, it is important to practice healthy prevention habits. Slowing the spread of germs by handwashing, wiping down surfaces, and staying away from infected people can help you avoid contact with the virus. You should also avoid touching your nose and mouth. Although these methods are not a guarantee, they do help. Other methods should be discussed with a healthcare practitioner who knows your personal history.