Here is a table to help you differentiate among flu, common cold, and allergic cold— Symptoms Cold Flu Airborne allergy Fever Rare Usual, high (100-102°F); lasts 3–4 days Never Headache Uncommon Common Uncommon General aches, pains Slight Usual; often severe Never Fatigue, weakness Sometimes Usual, can last up to 3 weeks Sometimes Extreme exhaustion Never Usual, at the beginning of the illness Never Stuffy, runny nose Common Sometimes Common Sneezing Usual Sometimes Usual Sore throat Common Sometimes Sometimes Cough Common Common, can become severe Sometimes Chest discomfort Mild to moderate Common Rare (except in allergic asthma)