5 Differences Between the Common Cold and Allergies

How to Tell The Difference Between a Cold and Nasal Allergy Symptoms

Woman blowing nose on couch wearing blanket
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The symptoms of the common cold and nasal allergies are often very similar, so it can be difficult to tell the two apart, even for a physician. Nasal congestion, runny nose, post nasal drip and sneezing can all be symptoms of nasal allergies or of the common cold. Other symptoms, as well as the timing or pattern of symptoms, and the response to various medicines are all a clue to determining whether symptoms are due to allergies or the common cold.

  1. Itching. Itching is typically a classic symptom of allergies, and is due to the release of histamine from mast cells present in the eye and nose. Itchy eyes, nose, and sometimes the ears and throat, are common features of allergies, but are rarely present with a cold. Find out more about how an allergic reaction occurs.
  2. Symptoms of systemic illness. Whole body symptoms, such as body ache and fever, are commonly associated with the common cold, and not present with allergies. Other symptoms, such as a sore throat and headache, are more commonly associated with the common cold than with allergies. Despite the term “hay fever”, allergies don’t actually cause a fever.
  3. Duration of symptoms. Allergy symptoms may last for as long as the trigger is present. For example, pollen allergies may last for an entire season and pet allergies last for the entire time the person is exposed to the particular animal. Cold symptoms usually last for a few days, and often resolve within a week or so.
  1. Associated symptoms. Other signs of allergic diseases, such as eczema or asthma, may suggest the presence of allergies. Since allergic diseases tend to occur together, it would be common for a person with nasal allergies to have other allergic conditions, including a history of eczema, food allergies or even asthma. A strong family history of allergies, such as in a person’s parents or siblings, could also be a clue to a person having allergies.
  1. Response to medications. The response to medications can also be helpful at differentiating allergies from the common cold. Allergy symptoms will usually respond to newer antihistamines, such as Claritin, Zyrtec and Allegra, while the symptoms of the common cold won’t. Older antihistamines, such as Benadryl, and decongestants, such as Sudafed, will typically help the symptoms of both allergies and the common cold.

Ultimately, it isn’t always obvious to tell the difference between allergies and the common cold. A physician, especially an allergist, may be able to detect differences between the two conditions by performing an appropriate physical exam. However, allergy testing is the only way to truly know if a person has allergies. Allergy testing is best performed as skin testing, which is typically performed by an allergist. Blood testing for allergies can also be performed, although is more expensive and less accurate than skin testing.  Watch allergy testing being performed.

Learn more about the symptoms, diagnosis and treatment of allergic rhinitis.


Buttram J, More D, Quinn J. Allergy and Immunology. The Complete History and Physical Exam Guide. 2003:53-69.

The American Academy of Allergy, Asthma, and Immunology. Accessed December 30, 2007.

DISCLAIMER: The information contained in this site is for educational purposes only, and should not be used as a substitute for personal care by a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition.

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