You’ve got a runny nose, a cough and congestion. So have you caught a cold or allergies? Unfortunately, it’s often hard to tell — even for doctors.
What Are Colds and Allergies?
Colds are caused by hundreds of different viruses. When one of these viruses gets into your body, your immune system attacks. Some of the effects of this immune response are the classic symptoms of a cold, such as congestion and coughing.
The germs that cause colds are contagious. You can pick them up when an infected person sneezes, coughs, or shakes hands with you. After a couple of weeks, at the most, your immune system fights off the virus and you stop having symptoms.
Allergies are caused by an overactive immune system. For some reason, your body mistakes harmless substances — such as mold or pollen — for germs and attacks them. Your body releases chemicals such as histamine, just as it does when fighting a cold. This can cause swelling in your nasal passages, a runny nose, coughing, and sneezing. Allergies are not contagious, although some people may inherit a tendency to develop them.
Differences Between Colds and Allergies
|
Characteristic |
Cold |
Allergy |
|
Duration |
3-14 days |
Days to months — as long as you are exposed to the allergen |
|
Time of Year |
Most often in the winter, but possible at any time |
Any time of the year — although the appearance of some allergens are seasonal |
|
Onset of symptoms |
Symptoms take a few days to appear after infection with the virus. |
Symptoms can begin immediately after exposure to the allergen |
|
Symptom |
Cold |
Allergy |
|
Cough |
Often |
Sometimes |
|
Aches |
Sometimes |
Never |
|
Fatigue |
Sometimes |
Sometimes |
|
Fever |
Rarely |
Never |
|
Itchy, watery eyes |
Rarely |
Often |
|
Sore throat |
Often |
Sometimes |
|
Runny or stuffy nose |
Often; usually yellow mucus |
Often; usually clear mucus |
Although there are some differences, cold and allergy symptoms overlap quite a bit.
