In Canada, 48,818 Canadians were diagnosed with the flu during the 2018-2019 season. (17) With illness being so prevalent, understanding the differences between the common cold and the flu is necessary for determining the best remedies and treatments for a speedy recovery.
What is the common cold?
The common cold is an illness caused by one of over 200 different types of cold viruses, typically affecting the nose and occasionally the sinuses, ears, and airways. The most common virus to cause common cold symptoms is usually referred to as the rhinovirus. (8)
The incubation period, the time from infection to symptom presentation, typically occurs within 24 to 72 hours, as the body recognizes and begins to fight the infection. (16) Symptoms of the common cold often include a sore throat, sneezing, and a stuffy nose. (13) These symptoms typically peak within a few days after infection and last for about a week; however, some individuals may experience symptoms for up to three weeks. (13)(15) Common cold symptoms occur when your immune system, the body’s main defense system, sends out white blood cells that release inflammatory mediators. The mediators prompt an increase in mucus secretion and induce sneezing reflexes as a method to remove the virus. (11)
What is the flu?
The flu is the common name for a respiratory infection caused by an influenza virus that infects to your nose, throat, and lungs. The average incubation period ranges between one and four days, with flu symptoms manifesting after two days on average. (5) The onset of flu symptoms occurs quickly and typically begins with a high fever (above 100°F or 38°C), body aches, and significant fatigue or weakness. (14) Though many individuals recover on their own, medical intervention may be required in severe cases in order to prevent complications. (14)
The virus that causes the flu is transmitted from one person to another through moisture, typically droplets that are spread when someone who is ill sneezes or coughs. The droplets can transfer via direct contact, but can also be contracted by touching an object, such as a telephone or doorknob, that has been in contact with a sick person. (14) What makes prevention difficult is that, due to the incubation period, people are often contagious before they show symptoms of illness. Therefore, hygiene practices, such as hand-washing and avoiding touching your face, are very important to reduce the transfer of germs during cold and flu season, or when you think you might be ill. (5)
The common symptoms
The common cold and the flu share several common signs and symptoms, making it difficult to distinguish between the two illnesses. Below is a list of the common symptoms you will see with each illness, so you have a better idea of whether you might have a cold or a flu. Determining whether you are sick with the common cold or flu can help you and your healthcare practitioner determine the best course of action for treatment.