If you develop congestion and a runny nose, it's understandable to wonder what could be behind your discomfort. Do you have a cold, allergies or something else entirely? It's not always easy to figure out.
There's a reason for the confusion: The way your body reacts to allergies and infections is similar, allergist and immunologist Dr. Tania Elliott, tells Yahoo Life.
"Your allergy cells are a component of your immune system," Elliott explains. "The reason why we see so much overlap in symptoms is viruses and bacteria can also aggravate and activate those cells."
When you're exposed to something you're allergic to, those allergy cells are activated and release histamine, which causes symptoms such as itchiness, redness, swelling and mucus production, Elliott explains. "When you have allergies that are untreated, what's happening is your immune system is constantly activated so you get a stuffy nose and increased mucus," she says. "Well, guess what? That is a perfect setup for an infection." Meaning, your allergies can actually cause an infection, such as a sinus infection, if they go untreated.
There are a few ways to tell allergies apart from a cold or other illness
Elliott recommends looking closely at your symptoms. "If you're feeling kind of crummy and you have congestion and a runny nose lasting longer than a week, the likelihood is that is an allergy," she says.
But, if you have a fever or swollen lymph nodes, it's likely an infection. "In general, allergies don't cause a fever or swollen lymph nodes," Elliott says. "If you're experiencing those symptoms, the likelihood is that it's an infection — it can be bacterial or viral." If so, that warrants a doctor's visit.
It's also important to know the symptoms of COVID-19, which can overlap with some allergy symptoms and infections. Along with congestion or a runny nose, COVID-19 symptoms can include fever, cough, shortness of breath, headache, muscle aches, sore throat, and new loss of smell or taste, according to the Centers for Disease Control and Prevention.
To make things a little complicated, however, you can have both allergies and an infection at once. "Sometimes there is an overlap," Elliott says. "What starts out as allergies can end up as a superimposed infection."
If you have facial pain or pressure in your sinuses, that could be due to underlying allergies, Elliott says. "However, if you notice it more on one side of your face, you have tooth pain or a metallic taste in your mouth, that could be a sign of an infection," she says.
How to treat your illness
The right treatment for you ultimately depends on what's causing your symptoms, Elliott notes. "When you have a virus or cold, symptoms tend to go away on their own," she says. "The best thing you can do is rest and hydrate and let it run its course." But, if you have a bacterial infection, you'll likely need antibiotics to clear it up, according to Elliott. In that case, your doctor will be able to help determine which one you're dealing with and recommend proper treatment from there.
If you have allergies, there are a few treatment options:
Avoid your allergy triggers. This, Elliott says, is the "first line of treatment," although it's not always easy to do.
Use an antihistamine. Antihistamine medications block the release of histamine, which causes allergy symptoms, Elliott says.
Try a steroid nasal spray. Steroid nasal sprays help decrease inflammation in your nasal passages and can help with congestion. It can take five to six days to notice an improvement, Elliott says, so consistency is key.
"If you're experiencing allergies, the over-the-counter aisle at the pharmacy can be a very scary place," Elliott says. "My recommendation is to see a board-certified allergist, get tested and curate a comprehensive treatment plan that's right for you."
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