According to Russell Foster, a professor of circadian (body clock) neuroscience at Oxford:
“Many people wake up at night and panic. I tell them that what they are experiencing is a throwback to the bi-modal sleep pattern. But the majority of doctors still fail to acknowledge that a consolidated eight-hour sleep may be unnatural. Over 30% of the medical problems that doctors are faced with stem directly or indirectly from sleep. But sleep has been ignored in medical training and there are very few centers where sleep is studied.”