You’re feeling crummy, with sneezing, sniffles, post-nasal drip… is it a cold, or are your allergies flaring up? It can be hard to tell them apart because they share so many symptoms.
Colds are caused by viruses and can lead to a runny/stuffy nose, congestion, cough and sore throat. (Note: The flu can also cause similar symptoms, but it also often comes with a high fever that lasts for three to four days, along with headache, fatigue and general aches and pain. These symptoms are less common when you have a cold.)
Allergies aren’t caused by a virus. They occur when your body’s immune system reacts to a trigger, or allergen, to which you are allergic. If you have allergies and you breathe in things such as pollen or pet dander, the immune cells in your nose and airways may overreact to these harmless substances. Your delicate respiratory tissues may then swell, and your nose may become stuffy or runny. Allergies also can cause itchy, watery eyes, which you don’t normally have with a cold.
Allergy symptoms usually last as long as you’re exposed to the allergen, which may be about six weeks during pollen seasons in the spring, summer or fall. Colds rarely last beyond two weeks. Check with your doctor if symptoms last beyond 10 days or if symptoms aren’t relieved by over-thecounter medicines.
Source: National Institutes of Health