The transition time from winter to spring can be kind of torturous. One day it's warm and sunny (finally!), and the next, we get some nice icy wind to warn us it's not time to break out the flip-flops just yet. Unpredictable weather turns getting dressed each morning into a huge ordeal. And it also creates the perfect environment for a case of the sniffles.

"The fluctuation of temperatures during the transition of seasons from winter to spring can cause an overlap of colds and allergies," Keri Peterson, M.D., an internist who works with digital health platform Zocdoc, tells SELF. "This can make it confusing for people to decipher which illness they are experiencing—particularly when symptoms first arise." Though allergies are most typically confused for the common cold, some people may also think they have a sinus infection or the flu. The problem is that treating the wrong thing can make you feel crummy for longer (and up your risk of becoming resistant to antibiotics from overuse).

In fact, many people with seasonal allergies don't know they suffer from them. "Often, we all become accustomed to living with mild symptoms and may not realize it until it is very severe or flared up," Purvi Parikh, M.D., an allergist/immunologist with Allergy & Asthma Network, tells SELF. Many people think they can’t possibly have allergies because they didn't have them as a kid. But Parikh says that it's actually very common to develop allergies as an adult. "Various factors such as increased exposure, or change in environment (moving from one city to another)," can lead to environmental and chemical allergies over time.

So how can you tell what's causing your runny nose? Here's how to ID the source, and why it matters.

There are a few unique symptoms for both a cold and allergies that can help you decipher what's ailing you.

"The number one differentiating symptom that patients experience with allergies is itchy eyes," Peterson explains. Some people may also experience itchy ears or an itchy throat, she adds. On the other hand, a cold can cause a low-grade fever, sore throat, swollen glands, and body aches. "You almost never experience these symptoms with allergies," Peterson explains.

Allergies also usually hit suddenly, whereas cold symptoms tend to show up gradually and worsen as the infection progresses. You also need to consider duration. "A cold typically lasts three to 10 days," Peterson says, so if your symptoms last longer than that, it's more likely you're suffering from allergies, "which can last for several months."

Your snot can also tip you off to what's going on. If your nose is runny and your nasal mucous is thin and watery, it actually could be either a cold or allergies, Peterson says. But thick and discolored (yellow or green) mucous is a clear indicator you've got some sort of respiratory infection, whether it's a cold or something bacterial, like a sinus infection.

It's important to know what's really going on because the treatments are so different.

A cold is a viral infection, and allergies are an immune response your body has to something in the environment. Since they're caused by completely different things, colds and allergies require different treatments. We know there's no cure for a cold, but you can do some things to help ease symptoms. "Treatments can include over-the-counter cold remedies such as pain relievers, nasal sprays to help with congestion, and throat lozenges to ease a sore throat," Peterson says.

Allergies, though, can be managed with anti-inflammatory medications such as anti-histamines and steroids, says Parikh. You can now buy popular allergy medications like Zyrtec, Claritin, and Allegra without a prescription. "Depending on the medication, most kick in within the same day and you improve over consistent use," Parikh says. She recommends using them regularly—for some patients who know they have extreme seasonal allergies, "we recommend daily use at the start of the season because it's much easier to control proactively rather than once allergies become very severe and unbearable," she adds. Some people may need a stronger treatment, like allergy shots, "which increase your immunity, and in some people, can cure your allergies through desensitization."

If you suspect you're suffering from allergies, but aren't sure about the best way to treat your symptoms, make an appointment with an allergist. Once springtime weather finally arrives, the last thing you want is an itchy, runny nose, holding you back from enjoying it.