Almost any level of alcohol consumption can cause sleep disorders and induce sleep disorders. Drinking alcohol can destroy the structure and duration of sleep, change the total sleep time, and affect the time required to fall asleep.
Although researchers do not fully understand all the complex functions of the body during sleep, we do know that lack of sleep can cause serious problems, including an increased risk of depression, heart disease, and other health problems.
We also know that excessive daytime sleepiness due to lack of sleep is related to impaired social and occupational functions, insufficient memory, and the risk of car accidents.
What is the normal sleep mode?
Normal sleep consists of two alternate sleep states, in which brain waves show different types of activities:
- Slow wave sleep (SWS), during which the brain operates very slowly, is a deep, peaceful sleep, usually accounting for about 75% of a night’s sleep
- Rapid eye movement sleep (REM), during which the eyes exhibit rapid movement, are not so calm, and are usually related to dreaming (REM occurs periodically during sleep and accounts for about 25% of young people’s sleep time; REM sleep onset It can be repeated for about 90 minutes, and one time lasts for 5-30 minutes.)
In addition, the study also identified transitional light sleep phases that occur at intervals during sleep.
Science does not know what function REM sleep has on the body, but it seems to be necessary for recovery. Some studies have found that when laboratory mice are deprived of REM sleep, it can cause death within a few weeks.
How the brain controls sleep
Initially, people thought that sleep was the result of reduced activity in the brain system that maintains wakefulness, but studies have shown that sleep is an active process of the brain, controlled by the nerve center of the lower brainstem.
Some of these nerve trunks produce serotonin, a chemical involved in sleep initiation and slow-wave sleep regulation. Other nerve cells produce norepinephrine, which has been found to regulate REM sleep and promote arousal.
It is not yet clear how these chemicals and other chemicals in the brain interact to control sleep, but we do know that drinking alcohol changes the function of these chemical messengers, thereby changing sleep patterns.
Alcohol and sleep
Many people with insomnia will have a drink before going to bed to help them fall asleep. After the initial stimulation, the sedative effect of alcohol can reduce the time it takes to fall asleep.
But the effects of alcohol don’t stop there. Studies have shown that drinking alcohol within an hour before going to bed disrupts the second half of sleep, causing people to fall asleep intermittently-waking up from a dream, unable to fall asleep easily.
Over time, the effect of drinking before going to bed will be worse. Studies have found that with continuous drinking, the sleep-inducing effect of alcohol weakens, while its sleep disturbance effects increase.
This is especially true for the elderly, because drinking alcohol produces higher levels of alcohol in their blood and brain than younger drinkers. Therefore, elderly people who have a drink before going to bed may increase the risk of falls and injuries if they wake up and walk at night.
“Happy Hour” Drinks
Studies have found that drinking alcohol even 6 hours before bedtime will increase wakefulness in the second half of sleep, even if the alcohol consumed has been excreted from the body.
Researchers believe that alcohol can cause long-term changes in the way the body regulates sleep.
Long-term alcohol consumption seems to be associated with an increased risk of sleep apnea, especially among drinkers who snore.
Obstructive sleep apnea is a disease in which the upper airway narrows or closes during sleep, leading to interruption of breathing. When this happens, the person will wake up, resume breathing, and then fall asleep again. The event of waking up after apnea may occur hundreds of times at night, thereby significantly reducing sleep time.
In addition, drinking a large amount of alcohol before going to bed narrows the air passages, causing apnea in people who usually do not show symptoms of sleep apnea.
Why is this effect of alcohol on apnea important? Sleep apnea patients who drink two or more glasses of alcohol a day are five times more likely to have fatigue-related traffic accidents than those who do not drink alcohol.
Research has linked sleep apnea, snoring, and alcohol consumption to increased risks of heart attack, arrhythmia, stroke, and sudden death.
As people get older, they naturally experience a decrease in slow wave sleep and an increase in nighttime awakenings. Studies have found that people over 65 usually wake up 3 or more times during the night.
This can cause sleep to become less peaceful and rejuvenated, and it will encourage the use of alcohol to try to increase sleep. However, the result is an increase in alcohol-related sleep disorders in the elderly.
Alcohol use disorder and sleep
For people with severe alcohol use disorders, sleep disorders may also include the following:
- Daytime fatigue
- Decreased sleep quality
- Wake up frequently
- Takes longer to fall asleep
It seems reasonable to think that patients with alcohol use disorder who quit drinking will return to normal sleep patterns, but in fact, abrupt cessation of drinking can cause alcohol withdrawal syndrome, which can lead to obvious insomnia and continuous sleep fragmentation.
Lack of sleep is one of the most common symptoms mentioned by people who quit drinking after drinking.
Alcohol withdrawal syndrome can cause the following conditions:
- Increased REM sleep associated with withdrawal hallucinations
- Reduce restful sleep
- Sleep consisting of short REM sleep
- Sleep interrupted by multiple awakenings
Recovery, sleep and relapse
After the withdrawal symptoms have subsided, the sleep patterns of people with alcohol use disorder will improve, but for some people, even after years of being awake, normal sleep patterns may never return.
Studies have found that people in the recovery period often have poor sleep, less slow-wave sleep, and increased wakefulness, resulting in less restorative sleep and daytime fatigue.
The irony is that if the recovering person restarts drinking heavily, their slow-wave sleep will increase, and their night awakening will decrease, at least initially. This false impression that drinking can improve sleep is the main reason for the relapse of many alcohol use disorders. However, the relief they received was only temporary.
As they continued to drink, their sleep patterns were soon disrupted again. The idea that drinking can improve sleep is actually just a myth.