Sleep problems are as old as mankind, but it has become more problematic than ever with the advent of modern technology resulting in "poor sleep hygiene". Exposure to bright light late at night results in falling asleep too late and sleeping too little, because it disturbs the body clock that is regulated by melatonin.

The amount of melatonin released by the hypothalamus depends mostly on exposure to bright and more specifically, blue light.
While reading books in bed may have been frowned upon for centuries, reading from a smart phone takes things to a next level. This can be remedied by reading from paper exclusively or installing a special program on your laptop (f.lux) or phone (Twilight) that takes out the blue sleep-disturbing light.
In day-time the reverse is true: make sure to get out in the sun for at least 30 minutes, preferably in the late morning if you want to combine it with producing enough vitamin D. Or, when it is too cold or dark for being outside for long, get daylight spectrum lights.
If that still doesn't help and you are sure to not suffer from apnea, get help from melatonin-based sleep supplements.

Melatonin is a hormone, released by the pineal gland that aids biorhythm regulation. The biorhythm can be disturbed by various causes among which stress and old age. Apart from treating sleep disorders, there's also evidence melatonin can help with tinnitis and irritable bowel syndrome.

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