We all wake occasionally during the night. We hear a noise — traffic or the chirp of birds — we fidget, there’s a flash of light or a change in temperature.
It is what researchers call “cortical arousal” — a brief period of unconscious wakefulness. And, though such arousals affect our heart rate, blood pressure and blood flow (cardiac haemodynamics), they are normal.
But when those nightly arousals become frequent, they can become a “burden.”
Click here to read full article https://www.dw.com/en/disrupted-sleep-linked-to-heart-disease-and-death/a-57266751