The difference between influenza and the common cold
Both influenza and the common cold are viral respiratory infections (they affect the
nose, throat, and lungs). Viruses are spread from person to person
through airborne droplets that are sneezed out or coughed up by an
infected person. In some cases, the viruses can be spread when a
person touches an infected surface (e.g., doorknobs, countertops,
telephones) and then touches his or her nose, mouth, or eyes. As
such, these illnesses are most easily spread in crowded conditions
such as schools.
Influenza is commonly referred to as "the flu." Between October and
March each year, between 10% and 40% of people are stricken with
influenza. Although most people recover fully, the flu causes
approximately 7,000 deaths annually in Canada, mostly among high-risk
populations (people with other medical conditions or weakened immune
systems, the elderly, or very young children). There are three types
of influenza viruses: A, B, and C. Type A influenza causes the most
serious problems in humans
There are over 200 different known cold viruses, but most colds (30-40%) are caused
by rhinoviruses. In Canada, the peak times for colds are at the start
of school in the fall, in mid-winter, and again in early spring.
Children catch approximately eight colds per year, adults catch
roughly four per year, and seniors about two per year.
Many people confuse the flu with a bad cold. The following table highlights the
differences between influenza and the common cold:
|
Symptom
|
Flu
|
Cold
|
|
Fever
|
Usually present, high (102-104°F or 38-41°C); lasts 3-4 days
|
Uncommon
|
|
Headache
|
Very common
|
Uncommon
|
|
Aches and pains
|
Common and often severe
|
Slight
|
|
Fatigue and weakness
|
Can last up to 14-21 days
|
Mild
|
|
Extreme exhaustion
|
Very common at the start
|
Never
|
|
Stuffy nose
|
Sometimes
|
Common
|
|
Sneezing
|
Sometimes
|
Common
|
|
Sore throat
|
Sometimes
|
Common
|
|
Chest discomfort, cough
|
Common
|
Mild to moderate, hacking cough
|
People infected with an influenza or cold virus become contagious 24 hours
after the virus enters the body (often before symptoms appear).
Adults remain infectious (can spread the virus to others) for about 6
days, and children remain infectious for up to 10 days.
|
