If you’ve been dealing with a runny, itchy nose and congestion for a few weeks now, it’s easy to wonder whether it’s the pollen or ragweed blooming outside that’s making you feel sick or an actual illness. It can be hard to tell the difference between a cold and allergies, especially when so many symptoms overlap and the cooler months often mean more germs are floating around. But…can allergies ever turn into a cold?
The answer is kind of complicated. Allergies and colds are totally different beasts with different causes, but they can exist within your body at the same time and trigger similar symptoms, says Christopher Brooks, MD, an allergist and immunologist at The Ohio State University Wexner Medical Center in Columbus, Ohio. Here’s the full breakdown, including how to manage and treat both conditions so you can feel better fast.
So, can allergy symptoms trigger a cold?
You may have heard some myths about allergies before, and this is one of them. Allergies don’t morph into colds. But you can definitely get both at the same time. And having unmanaged allergies can actually make you more prone to getting sick.
Here’s why: When your allergies are flaring, the tissues inside your nose, sinuses, and airways are inflamed and slightly weakened, Dr. Brooks says. As a result, “the tissue that lines our nose, sinuses, and airways is less protective, making it easier for invading viruses to enter cells and cause a cold.”
And inflammation and congestion from colds or allergies can also lead to sinusitis, when your sinuses swell up and block the flow of mucus, per the National Library of Medicine. That can cause symptoms like bad breath, pain or pressure around your eyes, coughing, fatigue, headache, and fever.
Certain allergy meds might make you more prone to getting sick, too. For example, oral steroids for very severe allergies can weaken your immune system and up your infection risk, per the Mayo Clinic. Certain injectable meds given for severe allergies (like omalizumab) can slightly raise your infection risk, too, Dr. Brooks adds.
What about standard over-the-counter (OTC) allergy meds or the ones your doc might prescribe for mild to moderate allergies? “We have not found that antihistamine allergy tablets, steroid nasal sprays, or antihistamine nasal sprays lead to more colds,” Dr. Brooks says.
In short: Allergies can’t “turn into” a cold, but they can make you more likely to catch one.
Below, we’ll dig into the differences between cold and allergy symptoms and how to treat each.
Allergy symptoms vs. cold symptoms
There’s definitely some overlap here, but the symptom list for allergies and for colds aren’t exactly the same, Dr. Brooks points out. Seasonal allergies can cause the following, per Yale Medicine:
- Congestion
- Sneezing
- Itchy eyes, nose, and throat
- Runny nose and eyes
- Post-nasal drip (drainage in the throat)
- Fatigue
- Coughing
And as for a cold? Symptoms can include the following, per Johns Hopkins Medicine:
- Stuffy, runny nose (that produces mucus)
- Scratchy, tickly, or sore throat
- Sneezing
- Watery eyes
- Low-grade fever
- Mild hacking cough
- Headache and muscle aches
- Fatigue
- Chills
3 ways to tell the difference between allergies and colds
First things first: Check if you have the urge to rub your nose and eyes. “Allergy symptoms often involve itching and cold symptoms do not,” Dr. Brooks says. (You may also have red eyes from allergies, too.) And a fever, while not always present with a cold, definitely doesn’t happen with allergies.
Pay attention to your symptom timeline, too. Colds usually start two to three days after a virus enters your body and then stick around from several days to several weeks, per Johns Hopkins Medicine. On the other hand, symptoms of seasonal allergies can last for weeks or months, most often during the spring or fall, per the American College of Allergy, Asthma, & Immunology (ACAAI). And if you have an allergy to something in your indoor environment that isn’t addressed (like mold or dust mites), you could have symptoms indefinitely, says Dr. Brooks.
Causes of allergies vs. colds
Allergies and colds happen for different reasons. Allergies happen when your immune system mistakes an irritant in the environment as a foreign invader. “This activates certain cells in our nose, sinuses, and airways to get inflamed and cause symptoms that we associate with allergies,” Dr. Brooks says. According to the Mayo Clinic and the ACAAI, allergies are often triggered by exposure to substances like pollen, grass, ragweed, pet dander, dust mites, or mold.
Colds, on the other hand, are caused by viruses that infect the tissue inside your nose, sinuses, and airways and cause inflammation. “The symptoms people get from colds are a part of the body’s defense. For example, when a patient gets a runny nose with a cold, it is their body trying to flush out the virus,” explains Dr. Books. According to the Mayo Clinic, you can catch a cold from the following:
- Breathing in tiny airborne droplets that are spread when a sick person coughs or sneezes
- Hand-to-hand contact with a sick person
- Touching surfaces or sharing objects that are contaminated with a virus, like doorknobs, remote controls, phones, cups, plates, utensils, or towels
- Touching your eyes, nose, or mouth after coming in contact with a virus
How to treat allergies vs. colds
While there’s not technically a cure for either one, there are plenty of things you can do to manage allergies and colds, so you can feel your best.
Some common treatments for allergies include the following, per Yale Medicine:
- Reduce your exposure to allergens if possible
- OTC or prescription antihistamines
- Decongestants to help relieve congestion
- OTC cough medications
- Prescription antihistamine or steroidal nose sprays
- Immunotherapy for severe cases, which helps your body build up a tolerance to certain allergens—this can be done in the form of injections or tablets dissolved under the tongue, under a doctor’s supervision
As for colds? It’s mostly about giving your body the support it needs to fight off the virus while keeping yourself as comfortable as possible. According to the Mayo Clinic, you can:
- Drink plenty of fluids, including warm drinks like tea, which can help fight mucus and sore throat
- Get lots of rest
- Run a humidifier to reduce congestion
- Try saline nasal drops to reduce congestion
- Take an OTC pain reliever or decongestant (which won’t help you get better faster but can help with fever and pain)
When to see a doctor
The severity of your allergy or cold symptoms will often determine whether you should get in to see your doctor. While most colds can be managed at home, for example, Dr. Brooks says you should call your doctor if:
- You have a fever
- You’re having trouble breathing
- Your symptoms haven’t improved after 10 days
- Your symptoms got better and then got worse again
- You have an underlying condition that makes you more prone to complications, like asthma or COPD, or if you’re immunocompromised
If lifestyle changes or home remedies for allergies aren’t helping, it’s worth looping your doctor in, says Dr. Brooks. They can confirm allergy testing to help you figure out exactly what you’re allergic to (and need to avoid) and may recommend prescription treatment options.
FAQ
How long does a sore throat from allergies last?
Throat inflammation and post-nasal drop can lead to a sore throat and coughing. This can happen anytime you’re exposed to your allergen, but it typically eases up a couple hours after exposure, according to the Cleveland Clinic.
Can allergies feel like the flu?
Yes, sometimes. Like the flu, allergies can give you a headache and make you feel congested and sluggish. But allergies won’t cause common flu symptoms like fever or body aches, per Dr. Brooks.
Do allergies mean my immune system is weak?
Nope! In fact, it’s quite the opposite. “Allergy symptoms stem from someone’s immune system being overly active. This is why allergies are most common among children, adolescents, and young adults, because this is when our immune systems are the strongest,” Dr. Brooks explains.
That said, having unmanaged allergies can make you more prone to catching colds, because nasal and airway inflammation from your allergy makes it harder for those tissues to fend off germs.
