Why is it so difficult to wake up?

Why is it so difficult to wake up? Sleep inertia, or wake-up grogginess, is the main reason you’re unable to fully wake up in the morning or after a nap. It’s a completely normal part of your sleep-wake cycle that’s intensified by factors like high sleep debt and circadian misalignment (caused by sleeping in, social jetlag, and travel jet lag).

Sleep inertia, or wake-up grogginess, is the main reason you’re unable to fully wake up in the morning or after a nap. It’s a completely normal part of your sleep-wake cycle that’s intensified by factors like high sleep debt and circadian misalignment (caused by sleeping in, social jetlag, and travel jet lag).