Is It a Cold, the Flu, or Covid?

Health

October normally marked the start of the influenza season, when cases of the virus increase significantly and remain high until the spring. However, over the past two years, there has been a lower number of flu cases than usual. This reduction is partially due to increased social distancing, mask-wearing and other measures in place to slow the spread of COVID. Those measures have proven to have the added benefit of slowing the spread of influenza.

In addition to COVID and influenza, many people still catch the common cold during fall and winter months. It can be confusing to know whether a sore throat and stuffy nose is due to a cold, the flu, COVID or something else.

While there are similarities between the three sicknesses, there are significant differences as well. Here are five points of differentiation between these illnesses.

1. Symptoms

COVID, colds and flu cause many of the same symptoms, including:

Cough
Fever
Headaches
Runny nose
Shortness of breath
Sore throat

With COVID-19 and the flu, symptoms may also include:

Chills
Diarrhea
Fatigue
Muscle or body aches
Vomiting

COVID-19 may also cause a loss of taste or smell. In addition, symptoms of the flu often come on fast. Cold symptoms tend to come on more gradually. COVID symptoms vary in the speed of onset.

2. Diagnosis

A test can determine whether an individual is infected with COVID or influenza. There is no diagnostic test for the common cold. At-home COVID tests should be repeated in a few days if the initial result is negative and symptoms remain.

3. Treatment

There are antiviral medications for both influenza and COVID-19. These medications help the body fight the flu or COVID symptoms and shorten the time an individual is sick with the virus. Antivirals also can help to prevent the spread of infection, by lessening the viral load in an individual. Antiviral medications do not “cure” the virus, however. Individuals will need to consult their primary care provider to see if they are an eligible candidate.

Rest, increased liquids and over-the-counter medications all can help to ease symptoms that come along with a cold, the flu or COVID.

4. Transmission

COVID is considered more contagious than the flu virus and has been observed to have more superspreading events than the flu. Additionally, if a person has COVID, they could be contagious for a longer time than if they had the flu.

COVID, the flu and the common cold are transmitted by droplets. This can be through large and small particles containing the viruses that are expelled when a person who is contagious coughs, sneezes or even talks. Precautions such as frequent hand washing, appropriate distancing and wearing face coverings can be effective in preventing the spread of these viruses.

5. Available vaccine

Vaccines are available for both COVID and the flu, but there is no vaccine available for the common cold.

The importance of the flu shot

Though the flu shot will not protect individuals against COVID, the vaccine has many other important benefits. Having more people vaccinated against the seasonal flu will decrease the amount of people who get seriously ill from the flu this winter.

The U.S. Centers for Disease Control and Prevention recommends flu shots for everyone ages 6 months old and up. Each year, the flu shot helps protect individuals against the dominant strains of the flu virus that experts predict will be the most active during the fall, winter and early spring months. Flu season typically begins in October and peaks in December and February – though cases can continue through the spring. It is safe to get a COVID booster and a flu shot at the same time. The 2022-2023 flu vaccine is available at doctors’ offices, pharmacies and clinics, and the CDC recommends getting the shot as early as September or October.

James D. Grant, M.D., is senior vice president and chief medical officer at Blue Cross Blue Shield of Michigan.