Some General Observations On Sleep

If you awaken shortly after falling asleep you cannot usually recall the few minutes before you fell asleep.

This explains why you often forget telephone calls or conversations in the middle of the night, or don't remember your alarm ringing in the morning if you go back to sleep after turning it off.

Since different chemicals influence sleep and wakefulness signals in the brain, foods and medicines that change the balance of these chemicals affect whether you feel alert or drowsy and how well you sleep.

Caffeinated drinks such as coffee, tea and some colas and drugs such as diet pills and decongestants stimulate some parts of the brain and can cause insomnia, or an inability to sleep.

Many sleeping pills and antidepressants suppress deep and REM sleep.

Heavy smokers often sleep very lightly and suffer reduced amounts of REM sleep. They also tend to wake up after 3 or 4 hours of sleep due to nicotine withdrawal.

Many people who suffer from insomnia try to solve the problem with alcohol - the so-called 'night cap'.

While alcohol can help you fall into light sleep, it also robs you of REM sleep and the deeper, more restorative, stages of sleep. Instead, it keeps you in the lighter stages of sleep, from which you can be awakened easily.

You lose some of your ability to regulate body temperature during REM sleep, so abnormally hot or cold temperatures in the environment can disrupt this stage of sleep.

If your REM sleep is disrupted one night, your body doesn't follow the normal sleep cycle the next time you doze off. Instead, you often slip directly into REM sleep and go through extended periods of REM sleep until you 'catch up' on this stage of sleep.