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You\u2019re feeling pretty lousy. You\u2019ve got sniffles, sneezing, and a sore throat. Is it a cold, flu, or allergies? It can be hard to tell them apart because they share so many symptoms. But understanding the differences will help you choose the best treatment.<\/p>\n
\u201cIf you know what you have, you won\u2019t take medications that you don\u2019t need, that aren\u2019t effective, or that might even make your symptoms worse,\u201d says NIH\u2019s Dr. Teresa Hauguel, an expert on infectious diseases that affect breathing.<\/p>\n
Cold, flu, and allergy all affect your\u00a0respiratory system<\/span>, which can make it hard to breathe. Each condition has key symptoms that set them apart.<\/p>\n Colds and flu are caused by different viruses. \u201cAs a rule of thumb, the symptoms associated with the flu are more severe,\u201d says Hauguel. Both illnesses can lead to a runny, stuffy nose; congestion; cough; and sore throat. But the flu can also cause high fever that lasts for 3-4 days, along with a headache, fatigue, and general aches and pain. These symptoms are less common when you have a cold.<\/p>\n \u201cAllergies are a little different, because they aren\u2019t caused by a virus,\u201d Hauguel explains. \u201cInstead, it\u2019s your body\u2019s\u00a0immune system<\/span>\u00a0reacting to a trigger, or allergen, which is something you\u2019re allergic to.\u201d If you have allergies and breathe in things like 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 stuffed up or runny.<\/p>\n \u201cAllergies can also cause itchy, watery eyes, which you don\u2019t normally have with a cold or flu,\u201d Hauguel adds.<\/p>\n Allergy symptoms usually last as long as you\u2019re exposed to the allergen, which may be about 6 weeks during pollen seasons in the spring, summer, or fall. Colds and flu rarely last beyond 2 weeks.<\/p>\n