Differences Between Allergies and Colds

Allergies and colds are conditions with different causes, evolutions, and treatments. Let's find out how you can tell them apart.
Differences Between Allergies and Colds

Last update: 13 August, 2021

Although they share some common symptoms, there are several differences between allergies and colds. People should be aware of these, as this will determine the treatment to follow. They’re also useful to implement habits that reduce the prevalence of episodes. Today we’ll show you their differences, although first let’s see what each one is exactly.

What are allergies?

Differences between allergies and colds include symptoms
Allergies are often caused by environmental triggers, and symptoms can range from mild and transient to severe enough to be life-threatening (anaphylaxis).

Allergies are a condition that occurs when the immune system reacts disproportionately to an external agent. These are known as triggers or allergens. The most common are insects, drugs, animals, or pollen.

According to the Asthma and Allergy Foundation of America, allergies are a chronic disease. That is, they last for years and often tend to get worse if left untreated.

The manifestation of symptoms, which are concentrated in the respiratory tract, mucous membranes, and skin, is called an allergic reaction. These appear minutes or hours after contact with the allergen.

Sometimes allergies can be confused with hypersensitivity. Researchers warn that these are two different conditions (for example, lactose intolerance isn’t a type of allergy). Among its most common variants we can highlight allergic rhinitis, allergic asthma, dermatitis and allergic conjunctivitis.

What are colds?

Colds are a type of respiratory tract infection, usually caused by a virus. Hundreds of viruses can cause colds, although the most common are in the rhinovirus family. Also known as the common cold, they’re the leading cause of absence from work and school worldwide.

As the Centers for Disease Control and Prevention (CDC) indicates, adults have an average of 2-3 colds per year. Children, having a more susceptible immune system, generally suffer from many more. It should not be confused with the flu, which causes more severe symptoms and can even be fatal.

What are the differences between allergies and colds?

We have already explained some basic differences between allergies and colds. These are further specified below based on specific criteria.


The causes of allergies are allergens; that is to say, substances that upon entering the body trigger an exaggerated response from it. Pollen, mites, dust, and dander are prime examples. On the other hand, viruses are what cause colds. These are tiny infectious agents that replicate by the thousands upon entering the body.


Patients confuse the two conditions because they share some signs in common. However, in practice, there are several nuances between them. The University Health Service, of the University of Texas (Austin), highlights the clinical manifestation of each condition.


  • Itching and tickling in the throat
  • Runny nose accompanied by itching
  • Sinus pressure
  • Itching, burning, and swelling of the eyes
  • Sneezing
  • It’s never accompanied by fever, body aches, or chills

A cold

  • Nasal congestion
  • Slight fever
  • Low-intensity pain in the body, accompanied by chills
  • Mild fatigue or weakness
  • Headaches (sometimes)
  • Sneezing

Despite the possible similarities, there are clear differences between allergies and colds. If you have an allergic reaction, you’ll never have a fever or chills accompanied by pain in the body. However, both signs are relatively common with a cold.


Although the above can help you suspect one condition or another, in reality, the duration of the symptoms is the main hallmark. This is pointed out by Harvard Health Publishing, which points out that colds generally don’t last more than two weeks. In fact, a healthy patient can overcome it between 7 and 10 days from the onset of symptoms.

Instead, allergies manifest as long as the patient is exposed to the trigger. Because of this, it isn’t uncommon for them to last for several weeks and even months. They can also be intermittent – occurring for only a day or two, and then returning when you have contact with the allergen again. This is usually chronic, so it will get worse if it isn’t treated properly.


Differences between allergies and colds include context
In winter, climatic conditions can favor a higher frequency of colds, something that is mistakenly associated with the cold.

Another way that you can differentiate between the two conditions is by context. Colds are often believed to develop from the cold, but, in reality, this isn’t the case. Johns Hopkins Medicine disproves this popular belief, pointing out that colds are more common during cold seasons for the following reasons:

  • People stay more in their homes or closed places, which favors the transmission of the virus.
  • Low humidity dries out the nasal passages, which removes one of the main barriers to preventing the entry of infectious microorganisms.

If you have been in contact with people with colds, you may also develop the condition. This doesn’t happen with allergies, as they aren’t infectious. In turn, they’re more frequent during certain seasons. Spring and summer are when the most cases are reported throughout the year.


Finally, treatment also occupies an important place regarding the differences between allergies and colds. In the case of allergic reactions, a therapy based on antihistamines, corticosteroids, decongestants and saline nasal rinses is used. However, medications are chosen according to the severity of the symptoms and on a case-by-case basis.

At the same time, the patient is advised to avoid the agents that have caused the reaction. This is done through habits such as keeping the home dust-free, reducing interaction with animals, or changing covers and bed covers on a regular basis.

For colds, the treatment is to counteract the symptoms. Specific medications are used for fever, coughs, headaches and general malaise. If the cold is very mild, even the use of these may be unnecessary.

Medications aren’t generally used to attack the virus, as the body gets rid of it on its own.

These are the main differences between allergies and colds. If you still have doubts about what type of manifestation you’re developing, we recommend that you contact an allergist to rule out any allergic reaction.

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