Up to 20 percent of adults may experience mild seasonal affective disorder, which can be caused by a disruption in the body's natural circadian rhythm, triggered by fewer daylight hours in winter, and may lead to disordered sleep patterns, according to a 2013 study in the Journal of Affective Disorders.

Another issue: sleep apnea! This condition, which is characterised by pauses in breathing, may worsen in winter because of upper-airway infections (associated with colds) and irritation from indoor-air pollution (which can increase when we shut our windows to seal in heat). But sweet dreams can be yours with a few simple adjustments to your routine. Here's what to do.

GET A WHIFF OF LAVENDER

The trick for deep sleep is using a lavender-scented diffuser in the bedroom. The scent has long been known to have sedative properties, decreasing heart rate and blood pressure. In fact, a Wesleyan University study found that women who sniffed lavender oil before bed experienced, on average, 22 percent more restorative slow-wave sleep.

BREAK A SWEAT

Though exercisers and non-exercisers clock about the same amount of sleep each night, according to a 2013 National Sleep Foundation poll, those who worked out rated their sleep as significantly better. Even light exercisers were 43 percent more likely to get a good night's rest than those who were mostly sedentary.

GO MEDITERRANEAN

According to a study in the European Respiratory Journal, people with moderate to severe sleep apnea who followed a Mediterranean diet-high in fruits, vegetables, whole grains, and fish-and walked at least 30 minutes a day for six months experienced roughly 18 fewer episodes of obstructed breathing per hour of REM sleep.

Given that excess belly fat increases the risk of sleep apnea, researchers attribute their findings to the decrease in waist circumference that resulted from the regimen.

CHECK YOUR MEDS

You already know to avoid caffeine close to bedtime, but some painkillers contain enough of the stimulant to keep you up at night. And certain antidepressants increase the levels of serotonin and norepinephrine-two neurotransmitters that can suppress REM sleep. If you think your prescriptions are affecting your zzz's, talk to your doctor about alternatives.

CHOOSE DINNER WISELY

A small study in The American Journal of Clinical nutrition found that adding food high on the glycemic index, like rice and potatoes, to your evening meal roughly four hours before bed could help you fall asleep 49 percent faster than a low-GI meal. High-GI foods increase the body's levels of the sleep-inducting amino acid tryptophan.

THE BEST POSITION

The winner?On your side.

According to the Better Sleep Council, stomach sleepers are most likely to report restlessness, while some studies have shown that sleep apnea is worse for people who snooze on their back.

Research in the Journal of Clinical Sleep Medicine suggests that people who spend 20 to 80 percent of the night on their back could have four fewer events of obstructed breathing per hour by simply rolling onto their side.

This article has been previously published in Oprah Magazine December 2013.

Photo: Collected