If not affected by a sleep disorder or a disruptor such as caffeine or nicotine, we all experience five stages of sleep, going from lighter to deeper and then into REM (rapid eye movement). These stages last 90 to 110 minutes each and recycle throughout our sleep experience.
Up until the 1950s, sleep was considered a passive state in which the brain rested, but we now know that the brain is active during sleep, processing learning and experiences from the day before (or days or years before) so that we can assimilate life’s experiences and cope with changes.
The stages of stage are labeled one through four and then REM. One is the lightest form of sleep, four the deepest, and REM is the state in which we dream most vividly. If awakened during REM, we will recall our dreams.
According to the National Institutes of Health (NIH):
“When we switch into REM sleep, our breathing becomes more rapid, irregular, and shallow, our eyes jerk rapidly in various directions, and our limb muscles become temporarily paralyzed. Our heart rate increases, our blood pressure rises, and males develop penile erections. When people awaken during REM sleep, they often describe bizarre and illogical tales – dreams.”
All the stages of sleep are essential to our full rest and rejuvenation, but many factors can disrupt these stages. You can have a sleep disorder such as obstructive sleep apnea (OSA), which can be treated, or you can experience side effects from medicines you consume that can disrupt your sleep pattern.
Caffeine and decongestants can stimulate parts of the brain that cause insomnia. Certain foods can also disrupt the brain’s sleep functions. Antidepressants can suppress REM. Smokers can experience nicotine withdrawals that cause them to awake after three or four hours and to sleep lightly overall. Drinking before bedtime, though it can make it easier to fall asleep, can disrupt the deeper stages of sleep as well as the REM stage.
Room temperatures that are too hot or too cold also can interfere with your sleep.
If you experience sleep problems for any reason, you need to be proactive and seek help. If following sound sleep hygiene guidelines don’t help, you should speak to your family physician or consult a sleep professional. Don’t let your nights rob you of a fully functioning daily life.