Why Do I Wake Up At 4 AM And Can’t Fall Back Asleep?

When you think about insomnia, do you imagine someone tossing and turning late at night, unable to fall sleep?

While that can happen, it only describes one iteration of the condition: sleep onset insomnia. Some research suggests that people with sleep onset insomnia are likely to have another sleep issue, like restless leg syndrome.

But there are other types of insomnia too, including one which makes people wake very early in the morning and stay up for hours after the disruption.

This is called terminal insomnia, also known as middle of the night insomnia, late insomnia, postdormitional insomnia, or sleep offset insomnia.

Per the University of Pennsylvania (UP), this happens when you wake up too early and aren’t able to fall asleep again.

Those with the condition usually get up hours before their set waking time. It’s common among older adults, who may face 4am wake-ups, a 2012 paper suggested.

UP pointed to some research that suggests this is a heritable trait (one you can get from your parents), though we can’t say for sure whether that’s definitely the case.

Ohio State University’s (OHU) Health & Discovery page added that terminal insomnia might happen due to our natural sleep-wake cycles, too.

“One likely explanation for waking up at the same time each night is that you go to sleep at the same time and then, at the same time each night, you reach a light stage of sleep and wake up,” they wrote.

Ageing may be another factor. The afforementioned 2012 paper reads, “older adults experience insomnia coupled with early morning awakenings due to an interaction between age-related changes in circadian rhythm timing coupled with behaviour changes that contribute to sustained poor sleep”.

Terminal insomnia might also be caused, or worsened, by:

• depression,
• anxiety,
• sleep apnoea,
• menopause,
• thyroid issues,
• acid reflux,
• hormones,
• fluctuating blood sugar levels.

It’s relatively normal to wake up in the middle of the night, OHU said. But it’s also expected that most people will be “able to return to sleep with little effort”.

If you’re waking up and unable to fall back asleep at least three nights a week, for at least three months, and if it negatively affects your daytime functionality, you have chronic insomnia.

Keep a sleep journal if you’re not sure whether this describes you.

Some lifestyle tweaks might make terminal insomnia less likely. These include keeping a regular sleep schedule, getting enough exercise in the day, avoiding caffeine and alcohol later in the day, and keeping your bedroom cool and dark.

The NHS advised speaking to your GP if your symptoms have been going on for months, if changing your lifestyle habits hasn’t affected your insomnia, and/or if it’s affecting your daily life in a way that makes it hard to cope.

If you suspect you might have another condition that’s causing your sleep issues, see your doctor sooner.