Allergies Vs. Cold: Here’s How to Tell the Difference
The symptoms for allergies and a cold are very similar, so we asked a team of experts for tips on how to tell the difference between the two.
A runny nose, sneezing, and coughing are all signs of a cold—but also of allergies. The two common conditions, which have similar symptoms, can affect both children and adults, but the treatments are quite different. Therefore, it’s important to understand the difference between a cold and allergies to seek proper medical care.
We asked a team of experts to share their tips on how to recognize the telltale signs of a cold versus allergies so you’ll know what to do when you’re sick.
One of the most obvious signs that allergies are to blame for your suffering is itchiness, explains Amy Shah, MD, an allergist based in Glendale, Arizona. “Itchy eyes, nose, ear, or throat are associated with allergies because of the compound histamine, which is what the body releases when allergy cells are activated and cause an itch,” she says. This is not a symptom you’re likely to suffer from if you’re dealing with a true cold. (Find out what allergists do to control their own allergies.)
Won’t go away: Allergies
If you have symptoms lasting more than three to five days, you’re likely suffering from allergies instead of a cold. “For a cold, the inflammation usually subsides when the infection has been successfully defeated by the body—usually a few days, but it can take up to one or two weeks,” says Matthew Mintz, MD, FACP, an internist in Bethesda, Maryland. “With allergies, symptoms can continue as long as the allergen is present. If you feel yourself experiencing cold-like symptoms more frequently, Dr. Shah recommends keeping a journal to see if there is a pattern. “It’s important to assess what your body is reacting to and treat it from there,” she adds. Also, consider that you might be showing these sinus infection symptoms.
Green snot: A cold
It’s not a bad idea to check the color and consistency of what comes out of your nose when you blow it. “In general, the nasal discharge in allergies is clear and watery,” says Dr. Mintz. “While a cold can also cause clear nasal discharge, it can often become yellow or even green.” One caveat, he explains, is that, like a cold, allergies can also cause a sinus infection, which is a secondary infection that, in turn, can produce a yellow or green nasal discharge.
Your eyes are watering: Allergies
If you find yourself battling bouts of itching and watering eyes, you’re most likely not dealing with a cold but, instead, are suffering from allergies. While it can be tempting to relieve the itch with your fist or fingers, Dr. Shah urges patients to keep their eyes as clean as possible. “Try rinsing out your eyes with water and using allergy drops whenever they’re nearby,” she says.
Fever: A cold
While it’s true that spring allergies are often referred to as “hay fever,” they’re not usually accompanied by an increase in body temperature that you see with a traditional fever. “Most allergies have nothing to do with hay, and people with allergies almost never have a fever,” says Dr. Mintz. “In contrast, when you contract a viral infection, one of the primary ways the body helps to fight the infection is by increasing the body’s temperature to kill the virus.” If your temperature rises above 101°F, you most likely have a cold.
Both colds and allergies can be seasonal, but allergies are far easier to anticipate than colds. “Allergies occur predictably at about the same time of year or whenever the offending agent of dust, mold, grass, pollen or pet dander is in your immediate surroundings,” explains Ian Tong, MD, chief medical officer at Doctor On Demand and clinical assistant professor at Stanford University Medical School. “This is usually during the spring when flowers are blooming and pollen counts are high.” (Find out 11 surprising ways you can stop seasonal allergies in their tracks.)
When symptoms hit: Allergies
While your cold might seem worse in the morning or night, you pretty much struggle all day long. Allergies are more linked to place: “Allergy to cats or dogs, for example, are typically apparent because they only occur when around the animals or their dander,” explains Gary Gross, MD, an allergist-immunologist at Texas Health Dallas. “If someone walks into a house with a cat and starts sneezing, an individual should suspect an allergy to cat dander.” Additionally, you may notice an increase in symptoms when you’re outdoor versus indoor, since grass, pollen, and weeds in the air may heighten exposure to seasonal allergies. (Here are 20 bizarre things you didn’t know you could be allergic to.)
Family history: Allergies
Allergies, like many medical conditions, tend to run in families. “Allergies are only seen in individuals who are genetically predisposed to allergic diseases,” says Dr. Mintz. “This is called ‘atopy,’ and atopic people usually have a family history of allergic diseases, such allergic rhinitis (allergies), asthma, or eczema.” Also, he adds that patients with allergic rhinitis will often have more than one allergic disease—for example, allergic rhinitis is very common in patients with asthma.
Muscle aches: A cold
Dr. Shah explains that allergies usually target your airways and not much else. Sore muscles can stem from your inflammatory cells attacking an infection—which indicates a cold. “Allergies are caused by a hypersensitivity in the body,” she says.
A sore throat: A cold
One of the best ways to tell the difference between allergies and colds is the presence or absence of a sore throat. “Colds are viruses that affect the upper airway,” Dr. Tong explains. “The virus can spread to the entire respiratory system including the throat, causing soreness. However, allergies are more associated with a raw feeling in the back of the throat rather than painful soreness.”
Skin rash: Allergies
Is there eczema present? “Eczema is an itchy skin irritation that is usually identified by a red, itchy, scaly rash,” says Dr. Shah. “If this is present or if you have a history of eczema, it’s likely allergies. The common cold should never present skin rashes unless a fever is involved.” (These are the signs of eczema you should never ignore.) Note, several viral syndromes, including hand-foot-and-mouth disease, which is caused by coxsackievirus, and roseola, also produce rashes that are different from eczema.
Coughing: A cold
Occasionally, a post-nasal drip from allergies could leave you hacking, but a cough typically indicates a cold—especially when it produces mucus, explains Dr. Tong. Pay close attention to the time of day that you’re dealing with your cough: If it tends to bother you only at night as opposed to throughout the day, allergies may be to blame. (Be sure to avoid these everyday mistakes that raise your chances of catching a cold.)
You’re always feeling lousy: Allergies
If you continue to get sick, despite the fact that you have very little interaction with other people throughout the day, you may be suffering from an allergy rather than a cold or viral infection, according to Purvi Parikh, MD, adult and pediatric allergist and immunologist at NYU Langone Health in New York City. Consider keeping track of the last few people you were in contact with and inquiring whether or not they are feeling some of the symptoms you are feeling. (Here’s what you might be doing to make your allergy symptoms worse.)
- Amy Shah, MD, an allergist, Glendale, Arizona
- Matthew Mintz, MD, FACP, an internist, Bethesda, Maryland
- Ian Tong, MD, chief medical officer at Doctor On Demand and clinical assistant professor at Stanford University Medical School
- Gary Gross, MD, an allergist-immunologist at Texas Health Dallas
- Purvi Parikh, MD, adult and pediatric allergist and immunologist at NYU Langone Health, New York City