Sleep expert reveals why you may be waking up at 3 a.m.

Lauri Leadley, a clinical sleep educator, says the hormone cortisol is likely behind your early morning wakeups.

"Cortisol is a hormone that serves as the body's natural alarm clock," explained Lauri, president of the Valley Sleep Centre, a clinic in Arizona.

Lauri explained everyone has a sleep wake cycle.

"In short, melatonin prepares your body for sleep, and cortisol prepares your body for awakening," she said.

"As cortisol begins to rise in the early hours, it's preparing your body — energizing it for wake time."

However, if your cortisol levels are already high, this rise in the hormone can be enough to wake you up prematurely.

"There are triggers that activate cortisol such as stress and anxiety," Lauri explained.

If your stress levels are high, your cortisol is likely to be higher, too.

And with high cortisol levels comes increased anxiety - which is why some people find all of their worst memories and fears playing out in the early hours.

"There's nothing worse than staring at the clock and thinking you have 3 more hours, but you just can't seem to quiet your mind," Lauri said.

However, the expert also notes that alcohol can play a big part in your 3 a.m. wakeups.

"Consuming alcohol before bedtime, or too close to bedtime can delay the natural release of melatonin," she said.

"Falling asleep under the influence and then waking up prematurely is typical.

"It may help you fall asleep, but when it wears off — just a few hours later — you'll wake up and usually that's somewhere in the middle of the night when you should be enjoying your natural REM cycle."

REM is one of the most important stages of sleep and is responsible for you feeling "refreshed" in the morning.

"I tell patients not to consume alcohol, caffeine, a heavy (protein) meal, sugar, or anything else that may trick your body into feeling energized or sleepy ... at the wrong time," she said.

If you're struggling with early morning wakeups, Lauri says you should "create a solid sleep plan.

"Taking a warm bath or shower, shutting down devices, no blue light, getting into a comfy bed, journaling, reading a book or magazine, practicing gratitude, praying or meditating," can all help tell your body it's time to wind down and get the sleep it deserves,"

And the key is consistency.

"Doing this with regularity will become a routine you love, appreciate, and look forward to each night," she added.