Feeling down during the darker, colder months of the year is often a diagnosable condition: SAD, or seasonal affective disorder. It’s grown increasingly common in years past, but this winter, health professionals expect an uptick due to various coronavirus pandemic restrictions that impede in-person socializing.

Here, with the help of health experts, we break down the signs and science of SAD, and what you can do to take care of yourself ’til that light at the end of the tunnel appears.

What Is SAD?

“Seasonal affective disorder is a change in mood that happens every year at the same time,” says John Whyte, M.D., Chief Medical Officer of WebMD. “Symptoms typically include depression, loss of energy, increased sleepiness, difficulty concentrating, irritability, and decreased sex drive.”

SAD is thought to affect between five and 10 percent of people, depending on what data you’re looking at, says naturopathic doctor Kasey Nichols, N.M.D. (Women are more likely to experience the condition.)

Though genetics play a role, certain lifestyle components (think: late-night Netflix binges) can also contribute to SAD, Nichols explains.

Read More: How To Balance Your Mood Through Times Of Change

People often experience SAD in the fall and winter as shorter days and more time spent inside limit their sunlight exposure. This lack of light then wreaks havoc on the circadian rhythm. You see, sunlight regulates our production of melatonin, which makes you sleepy, says Nichols. Without that regulation from light exposure at the right times, your sleep-wake cycle falls out of balance.

Although this experience is most common in the colder months, it is possible to get SAD in the spring and summer, too, says Whyte. However, experts admit there’s still much to learn about summertime SAD.

SAD And The Coronavirus Pandemic

It’s always important to stay in-tune with your mental health and mood. However, it feels especially crucial these days, given the stress of the current pandemic and limits on in-person gatherings.

“We know that increased stress and social isolation can predispose people to become depressed,’ says Nichols. “It’s important to be aware of your mood and how you feel right now due to social isolation, political change, and increased stress under the past few months.”

Read More: 7 Ways To Practice Self-Care That Don’t Cost A Dime

If you feel you might be susceptible to SAD or are concerned about how you’ll fare through a pandemic winter, be especially mindful of how spending more time inside, being away from friends and family, and working from home impact your mental health, Nichols suggests.

What To Do If You Think You Have SAD

If you think you might be experiencing SAD, a psychiatrist can help diagnose your symptoms and give you the most effective strategies for treatment.

“Treatment depends on the severity of symptoms,” says Whyte. “That’s why it is important to seek help. Antidepressants may help some people.”

A few lifestyle shifts can also help you avoid depressive feelings.

1. Light It Up

First things first: “Go get some sun,” says Whyte. “Get outside, especially in the morning after sunrise, to get natural light. Open those blinds as soon as you wake up.”

Nichols also recommends at least 20 to 30 minutes of bright sunlight exposure during the day. Get out for a walk in nature or around the block, or to play with your children in the backyard. “Sunshine has been shown to improve not only seasonal affective disorder but depression in general,” Whyte says.

Even on cloudy days, get out there, says Nichols. You may just need to spend a few extra minutes in the fresh air to make up for the lack of direct light,

If you can’t leave your home or office (or it’s straight-up gloomy out there), you might benefit from morning light therapy with a light box, Whyte says. Light therapy basically works to supplement sunshine. By exposing yourself to light early in the day, you let your body know when the day starts and it’s time to get moving.

Look for a light with 10,000 lux, which offers brightness comparable to a sunny day. “Research consistently shows that it is best for individuals that may be suffering from SAD to use lightboxes for 30 to 60 minutes in the mornings,” Nichols says. “Some studies report a 60-percent remission rate.”

2. Get Moving

As for exercise, Nichols says one hour of aerobic exercise three times a week helps fend off SAD. Anything that’ll get your heart rate up—and you’ll actually do—goes. Jogging, brisk walking, biking (whether outside or stationary), and quick lifts get the job done.

Don’t discount outdoor activities, either. Shoveling and skiing are straight-up aerobic workouts in themselves, too.

3. Nourish Your Body

Now, more than ever, eating a balanced diet of whole, nutrient-rich foods is a must. In addition to filling your plate with protein, healthy fats, and starchy and non-starchy vegetables, consider taking a daily multivitamin to avoid nutritional gaps and promote overall health.