Alcohol Suppresses Deep Sleep, and REM sleep! Alcohol will suppress the 3rd, 4th, and 5th stage of sleep, which will result in a very light, un-restful sleep. Reduced REM sleep usually leads to a REM sleep rebound, in the form of intense dreaming or nightmares, which weaken your sleep for days afterwards.
Considering that most people combine alcohol with coffee to fight hang-over, this is a deadly combination for your sleep system! Alcohol also dehydrates your body, so even small doses of it will produce un-restful sleep. As you remember, your blood vessels dilate during deep sleep to allow more blood flow to the muscles. If your body is dehydrated this process is much more difficult because dehydrated blood doesn’t flow as well through your blood vessels as fully hydrated blood.
Note: Never Combine Alcohol With Sleeping Pills! If You Do, You’re Risking Your life!
Source: The book – ‘Powerful sleep’