Two recent 2016 studies on sleep, showing

Again, of concern for those on night-shifts, varying shifts and emergency on-call workers.

A January 2017 study concludes that chronic sleep deprivation suppresses the immune system.


Our Scholars

It can be noted that, on the other hand, as regards excessive sleep, Ibn Sina is quoted as saying, in Avicenna’s Medicine that it "...causes dullness of psychological faculty, heaviness of brain, and cold diseases..."