Liquor's Sleep Aid: Why I Need A Nightcap

Alcohol is a depressant that can help you fall asleep faster, but its effects quickly wear off as your body tries to eliminate it from your system. It can be a stimulant in some cases, and it can fragment your sleep, reduce melatonin, and cause or worsen anxiety and sleep disorders. It can also trigger night sweats, and since it is a diuretic, it may cause you to wake up more frequently to use the bathroom.

Alcohol can be a stimulant, reducing your ability to fall asleep

Alcohol can be a stimulant, particularly in low doses, and this can negatively impact your sleep. While alcohol is known to make people feel drowsy, it can also be stimulating as blood alcohol levels rise, usually within the first hour of drinking. If you drink a low dose of alcohol, it can increase your heart rate, aggression, and impulsiveness, as well as cause a surge in dopamine levels.

Alcohol can also be stimulating if you drink it when your energy levels are naturally rising, such as in the early evening. This is one of alcohol's biphasic effects, meaning it can be stimulating and sedating at different times. The stimulating effects of alcohol can make it harder to fall asleep, and the sedative effects can wear off in the second half of the night, causing more nighttime awakenings. This is one reason why you might find yourself waking up in the middle of the night after drinking alcohol.

Additionally, alcohol can reduce the production of melatonin, the hormone that primes your body for sleep. One study found that melatonin levels were reduced by 15% two hours and 20 minutes after moderate alcohol intake and by 19% three hours and 10 minutes after alcohol consumption.

To improve your sleep, it is recommended to avoid alcohol at least three to four hours before bed. Some people may need more time, as drinking alcohol even six hours before bed can disrupt your sleep.

It can cause or worsen anxiety, making it harder to sleep

Drinking alcohol can cause or worsen anxiety, which can make it harder to sleep. Alcohol can induce panic due to its effects on GABA, a brain chemical that typically has a relaxing effect. Small amounts of alcohol can stimulate GABA and cause feelings of relaxation, but heavy drinking can deplete GABA, resulting in increased tension and panic. This is known as "hangxiety", a phenomenon that has also been referred to as "hangover anxiety", "post-beer fear", or "post-alcohol anxiety".

Alcohol is a depressant that slows down processes in the brain and central nervous system, initially making people feel less inhibited. However, these effects wear off quickly, and drinking can make people more vulnerable to anxiety disorders. As the alcohol leaves your system, you may go straight into 'fight or flight' mode, experiencing increased heart rate, sweating, or trembling. This can lead to a vicious cycle where you drink to relieve anxiety, only to feel more anxious as the alcohol wears off. Over time, this cycle can lead to alcohol dependence and worsening mental health.

Additionally, alcohol can interfere with the sleep cycle, reducing REM sleep in the first half of the night and causing more awakenings in the second half. It can also lower melatonin levels, the hormone that primes the body for sleep. This disruption to the sleep cycle can further exacerbate feelings of anxiety.

It can negatively impact your sleep cycle, especially REM sleep

Drinking alcohol before bed can negatively impact your sleep cycle, especially REM sleep. REM sleep, or rapid eye movement sleep, is important for dreaming, learning, and memory processing. It usually dominates the second part of the night.

Alcohol can cause a reduction in REM sleep, especially in the first half of the night. This reduction is more significant with high doses of alcohol, but even low and moderate doses can decrease total REM sleep. The onset of the first REM sleep period is significantly delayed, and this is the most recognisable effect of alcohol on REM sleep.

When you go to bed with alcohol in your system, you will likely experience more deep sleep and less REM sleep than usual. Later in the night, once your body has metabolised the alcohol, you will likely experience a rise in N1 sleep, the lightest stage of sleep. This can lead to frequent wakings and fragmented, low-quality sleep.

Alcohol can also cause or worsen anxiety, which may leave you wide awake in bed. It can trigger a vicious cycle, as sleep loss makes anxiety worse, which may cause you to self-medicate with more alcohol to relax.

Alcohol is a diuretic, meaning you'll wake up needing the bathroom

Alcohol is a diuretic, which means it promotes water loss through urine. It does this by inhibiting the production of a hormone called vasopressin, which plays a large role in the regulation of water excretion. Vasopressin tells your kidneys to reabsorb water if it’s needed by your body, rather than flush it out through the bladder. But the way alcohol interferes with this natural signal, switching it off, means the bladder is free to fill up with urine, which ends up making you need to pee more often.

Getting up to go to the toilet at night can disrupt your sleep too. And that’s on top of the effect alcohol has in disrupting the restorative REM stage of sleep, so cutting back on alcohol – especially before bed – can mean you wake up feeling fresher.

Alcohol makes us pee more and more frequently, and fluid leaving our bodies at this rate can lead to dehydration if not replaced. It is important to replace lost fluid by drinking water if we choose to drink alcohol.

Dehydration is more likely in hot weather even without drinking alcohol, so this is especially important if you are drinking when the weather is hot. Heatwaves can be dangerous in their own right – and adding alcohol to the mix increases your risk of dehydration, heat exhaustion or heat stroke.

Dehydration can become serious and lead to confusion and seizures. Serious dehydration requires urgent medical attention. The effects of dehydration include feeling thirsty, dizzy, lightheaded and tired, experiencing a dry mouth and lips and dark yellow and strong-smelling pee.

Dehydration makes hangover symptoms worse too. It’s important to replace lost fluid by drinking extra water if you choose to drink alcohol.

It can cause sleep disorders, including insomnia and sleep apnea

Alcohol can cause sleep disorders, including insomnia and sleep apnea. Research has shown that heavy drinkers have a 64% greater risk of insomnia, while less frequent binge drinkers are 35% more likely to develop insomnia than non-drinkers. Even moderate amounts of alcohol are associated with decreased REM sleep duration, increased wake after sleep onset time, a longer time to fall asleep, and a lower percentage of time in bed spent sleeping.

Alcohol can also increase the risk of sleep apnea by 25%. Sleep apnea is a sleep disorder that causes breathing to repeatedly stop and start while sleeping, resulting in loud snoring with occasional gasping, choking, or snorting sounds. It can lead to daytime sleepiness and low energy. Alcohol relaxes the muscles in the airway, causing obstructions in the upper airway and triggering sleep apnea episodes.

Additionally, alcohol can worsen existing cases of sleep apnea. It increases the time between when a person stops breathing and "wakes up" to breathe again, and it can also cause nasal congestion, making it even harder to breathe through the nose. For those with central sleep apnea, alcohol further reduces brain activity, leading to more frequent pauses in breathing.

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