Cold or flu: what's the difference?

Sneezing, sore throat, stuffy nose…are these cold or flu symptoms? Here are some clues to help you distinguish these two respiratory infections and a few tips to ease the symptoms they cause.

What is a cold?

A cold is a minor infection of the nose and throat. It is caused by six different types of viruses, with approximately 200 variants. Once you are infected by the virus, it causes swelling of the tissues lining the mouth, throat and nose. The telltale signs of a cold are sneezing, sore throat, runny nose and nasal congestion.

Colds spread through virus-laden droplets from the nose and mouth released into the air when an infected person coughs or sneezes. The incubation period lasts one to four days, but those infected are contagious before the onset of symptoms and remain so for approximately six days (10 in the case of children). The common cold also spreads through indirect contact, since viral particles can survive several hours on objects (phones, door handles, toys, etc.),

It generally takes seven days for the immune system to fight off a cold. Preschoolers  will catch five to seven colds each year, compared to two or three for adults.

What is a flu?

Influenza, more commonly known as the flu, is a respiratory infection caused by a virus. It is as contagious as a cold and can affect up to 25 percent of the population every year. Some of its symptoms, such as coughing, sore throat and sneezing, are the same as those of the common cold.

In addition to a sore throat and cough, however, the flu also causes fever, headaches, muscle aches and fatigue. Easing these symptoms will help a person recover. It generally takes one or two weeks to get over the flu. Some people are more at risk of developing complications, such as ear infections, pneumonia or bronchitis.

Every year, close to 75,000 Canadians are hospitalized due to flu-related complications and 6,700 of them will die as a result. In some cases, antiviral drugs may be prescribed to treat the flu in certain groups of people. Ask your pharmacist for more details.

Possible treatments

• To prevent dehydration and help liquefy thick mucus, drink plenty of fluids and run a cool-mist humidifier to keep the air moist.
• Stay home to rest and avoid spreading the infection to others.
• To ease a sore throat, gargle with salt water (four times a day: ½ teaspoon of salt in 250 ml of water) and suck on sugar-free lozenges or ice.
• To soothe a dry cough that could irritate your throat, drink herbal tea or chicken broth.
• Use cold or warm steam inhalation to relieve chest congestion.
• Try saline mist to clear nasal passages and sinuses.

The flu vaccine

Vaccination is the best way to prevent the flu. The vaccine (or “flu shot”) provides immunity against the virus about two weeks after being administered and is 80 percent effective in healthy children and adults. It does not, however, provide protection from all strains of the flu or from the common cold.

Habits to be taken in prevention

Here are some ways to help you prevent the cold and flu:

• Try to stay away from people infected with these viruses.
• Wash your hands often – with soap and water, or if you do not have access to water, with an alcohol-based hand sanitizer.
• Avoid touching your eyes, nose and mouth with your fingers. Use the back of your hand or paper tissues instead.

To avoid the spread of infection:

• Sneeze into a paper tissue or your elbow.
• Avoid touching others, especially people in poor health.

To learn more:

Flu: A Serious Infection, Ministère de la Santé et des Services sociaux du Québec.