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What are the differences between cold symptoms and allergy symptoms?

Allergies are a response by your immune system to a foreign substance, such as a food, an insect bite or something in the air (pollen or dust, for example). Your immune system mistakenly identifies the substance (or allergen) as harmful to your body and tries to fight it off. A cold, on the other hand, is a viral infection of the respiratory system (the system of organs and tissues that enables you to breathe).

Symptoms of colds and of allergies can appear quite similar, and include runny nose, sneezing, itchy, watery eyes, nasal congestion and cough. You may wonder how to know which malady you're suffering from -- and if you don't know what you have, you don't know how to treat it.

Here are some basic differences between cold symptoms and allergy symptoms:

  • Allergies do not cause fevers. Colds do.
  • Discharge from a runny nose caused by allergies is thin and colorless. With a cold it may be thick and yellow.
  • Allergy symptoms begin immediately upon exposure to the allergen. Cold symptoms begin one to three days after you're exposed to the cold virus.
  • Allergy symptoms will persist until you're no longer exposed to the allergens. A cold will go away after five to seven days.
  • Allergies may also cause rashes, gastrointestinal distress (vomiting, nausea, stomach cramps and diarrhea) and other symptoms that are not caused by a cold.

There are no medications you can take to treat the common cold. You can take over-the-counter medications such as antihistamines, decongestants, anti-inflammatories, antitussives and expectorants to help alleviate your symptoms. You can also use various home remedies such as inhaling steam and gargling warm saline.

If you think you may have allergies, you should see an allergist and get tested to find out exactly what you are allergic to. The best way to get rid of allergy symptoms is to avoid contact with the allergen or allergens. Your doctor may also prescribe medications to help you with your symptoms.