Sleeping patterns data collected over hundreds of consecutive days found that, across three distinct, geographically isolated groups, people slept for roughly 5.7–7.1 continuous hours each night.

Getting a good night's sleep is supposed to help you recharge and wake up ready to take on the day. But for me, and plenty of other people, lying down doesn't always mean falling asleep.

Waking up with your heart racing can be distressing, but it’s not necessarily a sign of something serious. Anxiety, not sleeping enough, or heart arrhythmia may be the cause.