It is sometimes hard to tell because a lot of the symptoms may overlap. Here is a great chart from webMD that summarizes the difference:
Characteristic
|
Cold
|
Allergy
|
Duration
|
three-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
|
Last year, I did a Q&A with my cousin, Dr Joann Lin, who is an allergist in Dallas, TX. If you have further questions you want to ask, you can email them to me at ellenkimmd@gmail.com and I'll compile another Q&A post with her.
