The common cold. The flu. The “stomach” flu. With all the different terms for respiratory illness going around, it can be difficult to keep them straight.

It’s important to know the basics of influenza so you can take the necessary steps to prevent disease for both yourself and those around you. This article helps outline the differences between some of the common terms and provides a breakdown of what key things you need to know about one of the most common respiratory diseases, the flu.

Influenza, or the flu as many call it, is a contagious respiratory illness caused by a group of viruses known as influenza viruses. There are two main types of influenza that affect humans – influenza A and influenza B. Both these viruses cause similar illness but are different in the ways that they cause disease.

Influenza A

Influenza A viruses are more common than influenza B viruses and are the only influenza viruses known to cause flu pandemics (i.e., global epidemics of flu disease).

Influenza B

Influenza B viruses are less common than influenza A viruses, but still circulate at high levels each flu season. Influenza B viruses have not been known to cause flu pandemics.

The flu is among the most common viral respiratory diseases, and it can affect anyone – including healthy people. In fact, it’s so common, a 2018 study suggested that an average of about 8% of the U.S. population gets ill from the flu each season.

The Centers for Disease Control and Prevention (CDC) estimates that from Oct. 1 – Nov. 25, 2023, there have been at least 1.8 million illnesses, 17,000 hospitalizations and 1,100 deaths from influenza so far this season in the United States. While the flu can infect anyone, some individuals are more likely to get sicker or develop other complications after getting the flu.

Adults 65 years or older, those with certain chronic medical conditions and pregnant individuals are at increased risk of developing severe complications from the flu, meaning they are more likely to get very sick, be hospitalized or die from their infection. This is why influenza prevention, including an annual flu vaccine, is so important in protecting yourself and your loved ones.

You may have heard people use the term ‘stomach flu’ to describe an illness associated with nausea, abdominal pain/cramping or diarrhea. However, this can be a bit misleading, as having influenza (the flu) is not the same as having the stomach flu.

The Flu VS The Stomach Flu
Caused by influenza viruses Commonly caused by noroviruses
Spreads through respiratory droplets Spreads through contact with infected individuals or contaminated food/surfaces
Causes respiratory symptoms Causes gastrointestinal symptoms
Symptoms include:

·         Fever or feeling feverish/chills

·         Cough

·         Sore throat

·         Runny or stuffy nose

·         Muscle or body aches

·         Headaches

·         Fatigue (tiredness)

Symptoms include:

·         Diarrhea

·         Vomiting

·         Nausea

·         Stomach pain

·         Fever

·         Headache

·         Body aches

There is a seasonal vaccine to protect against influenza. There is currently not a vaccine to protect against norovirus.


The flu spreads through respiratory droplets, which are tiny droplets that are made when people cough, sneeze or even talk. These droplets can spread the virus to others when they land in the mouth or noses of people who are nearby. This makes covering your cough or sneeze especially important in stopping the spread of influenza or other illnesses.

The best and easiest way to protect yourself and those around you from influenza is to get the influenza vaccine each flu season. The flu vaccine prevents millions of illnesses and visits to the doctor each year. For example, during 2019-2020, the last flu season prior to the COVID-19 pandemic, flu vaccination prevented an estimated 7.5 million influenza illnesses, 3.7 million influenza-associated medical visits, 105,000 influenza-associated hospitalizations and 6,300 influenza-associated deaths.

Individuals who get the flu vaccine may still get influenza during a normal flu season; however, flu vaccination has been shown to reduce the severity of illness. The flu vaccine decreases your likelihood of getting sick with the flu. If you do get sick, you are less likely to have severe illness, including illness leading to hospitalization. The vaccine also helps protect those around you by reducing the spread of the virus; since the flu vaccine can prevent you from getting the flu, you are then less likely to spread it to others. This includes those who are too young to receive the influenza vaccine (those under six months of age) and those with certain chronic medical conditions, who may be at higher risk of complications from the flu.

Vaccination is the best way to protect against influenza infection and severe illness. Everyone ages six months and older should get their flu vaccine each year to provide the best protection against the flu. For more information on finding a flu vaccine near you, visit or contact your health care provider, local public health department or pharmacist.

If you do get the flu, it’s important to rest and drink plenty of fluids. Your body needs lots of rest to recover, and fluids are essential for helping to flush out toxins and keep your body running smoothly.

Remember, the flu can be a serious illness and it’s important to take it seriously. If your symptoms don’t improve or if they get worse, make sure to contact your health care provider right away. They can recommend the best course of action and help ease your symptoms. Don’t forget to practice good hygiene and to avoid close contact with others while ill.

There are medications that can shorten the duration or severity of your illness and help your body fight influenza. Antiviral medications can help treat the flu and might be prescribed by your health care provider if you are at increased risk for complications from the flu. Over-the-counter medications such as ibuprofen and acetaminophen can also help to reduce congestion, fever and body aches associated with the virus. Be sure to read the label and follow the prescription instructions or directions carefully.

Six tips for flu prevention

While getting the flu vaccine each year is the best method of protection against influenza, there are many other ways you can prevent the spread of respiratory illness.

  1. Avoid close contact with people who are sick. If you are sick, limit contact with others as much as possible to keep from infecting them.
  2. Wash your hands often and thoroughly, preferably with soap and water.
  3. Cover your cough and sneezes.
  4. Avoid touching your eyes, nose and mouth.
  5. Clean and disinfect surfaces and objects that may be contaminated with viruses that can cause the flu.
  6. If you are prescribed influenza antivirals, take them as recommended.


Influenza | HHS
Flu Treatment | HHS
Flu Vaccine Benefits | CDC
Flu Activity & Surveillance | CDC
Seasonal Incidence of Symptomatic Influenza in the United States | Oxford University Press