People who suffer from a rare form of insomnia can die from lack of sleep.
A genetic disease called fatal familial insomnia, or FFI, causes people to fall into a state in which they are neither asleep nor awake. Since they cannot fully sleep, they suffer from exhaustion, dementia and eventually death. There is no cure.
According to ABC News:
"The genetic mutation for FFI runs in families. Only 40 families are known to have this disease in the world, but most people have had at least one night where it seems impossible to fall asleep.”
A lack of sleep clearly wreaks havoc with many facets of human health. Scientists have long known, for instance, that lack of sleep is associated with weight gain. One study found that after a night of abbreviated sleep, subjects consumed more than 500 extra calories.
Another study also found that subjects ate significantly more snacks and carbohydrates after a night of only five and a half hours of sleep.
According to the New York Times:
“Some studies pin the blame on hormones, arguing that decreased sleep creates a spike in ghrelin, a hormone that stimulates appetite, and a reduction in leptin, which signals satiety.”