Cold vs. Allergies Guide: Comparison of Symptoms

Published August 9th, 2021 by Chris Riley
Fact Checked by
Camille Freking
Medically Reviewed:
Dr. Angel Rivera

Colds and allergies are both common medical conditions that contribute to uncomfortable symptoms like nasal congestion, sneezing, and a runny nose.

However, if you have never been diagnosed with allergies before, how can you be sure which condition you’re suffering from and what the best course of treatment is?

This cold versus allergies guide will tell you everything you need to know about the causes, symptoms, and treatments for each condition.

Causes

Cold and allergy symptoms occur for different reasons, as they have different causes. Because of their different causes, colds may be more likely to occur at different times of the year than allergies.

Allergies

The term “allergies” is commonly used to describe symptoms of allergic rhinitis, also referred to as hay fever. While people can be allergic to many different substances that contribute to a variety of different symptoms, the symptoms that most people associate with allergies primarily concentrate in the nose and sinuses.

These symptoms are caused by exposure to an allergen. Allergens are substances that most people find harmless but that can cause an immune response in others.

For example, pollen is not dangerous and does not cause symptoms in many people, but people with allergies to pollen can experience allergy symptoms when exposed. Common allergens include mold, pollen, dust mites, and pet dander.

Some allergens, such as pollen, are prevalent only during certain times of the year. When a person has a reaction to these allergens, they are said to have seasonal allergies.

Other allergens, such as pet dander, are prevalent throughout the year and contribute to perennial, or year-round, allergies.

Allergy symptoms occur when a person is exposed to an allergen. When exposure occurs, the person’s immune system mounts a defensive response and starts to produce antibodies that work to attack and neutralize the allergen. A chemical called histamine is produced, which causes certain symptoms, such as nasal inflammation, increased mucus production, and watery eyes, among others.

Cold

While allergies are caused by an immune response to exposure to an allergen, the common cold occurs as a result of an infection from one of hundreds of different types of viruses. Although many different viruses can cause the symptoms associated with the common cold, among the most common are a family of viruses called rhinoviruses.

While allergies are not contagious, colds are highly contagious and can be passed from person to person through droplets of moisture in the air. If you are in the presence of a person who is sick, you’re exposed to the virus when the person sneezes, speaks, or coughs. These tiny droplets of moisture contain the virus and can infiltrate through a person’s mouth or nose as they breathe, or even through the eyes.

Symptoms begin to occur when the body detects the presence of the virus and starts to mount an immune response. Colds can also be contracted by touching something that is covered in droplets that contain the virus, such as a person’s hand or shared surfaces, such as a cup, faucet, or door knob.

Symptoms

It can be challenging to determine whether you’re experiencing a cold or allergies, as there are numerous overlapping symptoms between the two conditions. 

However, there are some important distinctions.

Allergies

Allergies are characterized by symptoms that include:

  • Sneezing
  • Runny or stuffy nose
  • Itchy, watery eyes
  • Nasal congestion

The above symptoms usually occur as a part of allergies. However, there are other symptoms that may or may not occur. These include:

  • Cough
  • Fatigue
  • Sore throat

One of the most significant differences between cold symptoms and allergy symptoms is that allergies are never associated with a fever or body aches. 

If you think you might be experiencing allergies but have a fever or body aches, you are likely to be suffering from an infection, such as a cold or other upper respiratory tract infection.

Another important difference between allergies symptoms and cold symptoms is that allergies symptoms begin as soon as an individual is exposed to an allergen. By contrast, cold symptoms typically take a few days to develop after an individual is exposed to the virus.

Allergy symptoms can occur at any time of year if a person suffers from perennial allergies, such as allergies to mold, pet dander, or dust mites. However, seasonal allergies are more likely to occur in the spring or fall when certain plants are in bloom and spreading pollen. If you experience symptoms around the same time each year, it’s likely that you have seasonal allergies.

The timeline on which allergy symptoms are experienced also differs from cold symptoms. Allergy symptoms are likely to continue as long as a person is exposed to an allergen unless they take medication to prevent or treat their symptoms. The symptoms typically continue for a short period of time after allergen exposure ends, then resolve on their own.

As a result, people can experience allergy symptoms for a short period of a few hours to months or even longer. Those with prolonged exposure to an allergen, such as people who live in a house with pets and have an allergy to pet dander, will continuously experience allergy symptoms until the allergen is removed or the person receives proper treatment.

Cold

The symptoms most commonly associated with a cold include:

  • Coughing
  • Sore throat
  • Runny or stuffy nose
  • Nasal congestion

There are some symptoms that may or may not occur when you have a cold. These include:

  • Body aches
  • Fatigue

Unlike allergies, which never cause a fever, a cold may cause a fever in some people. Colds also may cause itchy, watery eyes, but this symptom is uncommon and is usually more indicative of allergies. If you have itchy, watery eyes and no other symptoms, it’s likely to be caused by allergies instead of a cold.

As noted above, cold symptoms typically take several days to develop after an individual is infected with the virus. While you are most likely to catch a cold during the colder months of the year (hence the name), the viruses that cause a cold are always present, so it is possible to get sick at any time of the year. Cold symptoms are commonly experienced for anywhere from three days to two weeks.

Treatment

Because colds are caused by viruses and allergies are caused by exposure to an allergen, there are different treatments that are appropriate for each condition. Because some symptoms of colds and allergies overlap, medications with the same active ingredients are sometimes helpful in the treatment of each condition.

Allergies

The best treatment for allergy symptoms is prevention. If possible, minimizing or eliminating exposure to the allergen that causes symptoms is preferred, but it may not always be possible. 

For example, people with allergies to ragweed, a common type of pollen, are unlikely to be able to avoid spending any time outdoors for several months of the year. However, it may be possible to adjust their routines to exercise indoors and minimize time spent outside.

In situations where it is impossible to completely eliminate exposure to a specific allergen, medications can be used to control symptoms.

There are both over-the-counter medications and prescription drugs available to treat allergies, including drugs classified as corticosteroids, antihistamines, and decongestants.

  • Corticosteroids include active ingredients like fluticasone. Commonly administered in the form of a nasal spray, these medications work by reducing inflammation in the tissues that line the nasal passages and sinuses, which helps to minimize congestion. These medications work best when used daily over a long period of time and are not typically recommended for acute symptom treatment.
  • Antihistamine medications help to treat allergy symptoms by blocking the action of a chemical in the body called histamine that is known to cause allergy symptoms. One of the most common antihistamines is diphenhydramine, a fast-acting active ingredient that is found in medications like Benadryl. These medications work well for the treatment of acute symptoms.
  • Decongestant medications work to treat allergy symptoms by narrowing the blood vessels that line the nasal passages. During an allergy attack, these blood vessels widen, causing inflammation and increased production of mucus, which contributes to congestion and sneezing. Decongestants commonly used to treat allergy symptoms include pseudoephedrine. 

Colds

Because allergies and colds have some symptoms in common, including sneezing, nasal congestion, and runny nose, some of the same medications can be used to treat each condition.

Corticosteroids, antihistamines or decongestants may be recommended to treat the symptoms of a cold, although they will not eliminate the virus, which needs to run its course.

In addition to using these medications to treat symptoms of nasal congestion, the use of over-the-counter pain relievers and fever reducers, such as ibuprofen or acetaminophen, can help alleviate discomfort caused by a headache, low-grade fever, or body aches.

Consult a healthcare provider to determine the best treatment options for your particular symptoms. 

Summary

Although colds and allergies share many of the same symptoms, including nasal congestion, runny nose, and sneezing, there are some important differences. Allergies will never cause a fever or body aches, while a cold will only rarely cause itchy, watery eyes and only in conjunction with other symptoms.

The nasal symptoms associated with both allergies and colds can be treated with similar medications, including corticosteroids, antihistamines, and decongestants, while cold symptoms may also be aided by pain relievers and fever reducers.

It is best to consult a healthcare provider to help determine the best medicine for you.

References and Sources:

Allergies and the Immune System | Johns Hopkins Medicine 

Common cold - Symptoms and causes | Mayo Clinic 

Acetaminophen | U.S. National Library of Medicine 

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