Does alcohol make you snore?
It can. In a 2018 analysis of 14 trials, alcohol before bed added about 2 breathing pauses or shallow breaths an hour of sleep. In people who already snore it added about 4, and in people with sleep apnea about 7.
Snoring after a few drinks gets treated as a joke, and the person doing it usually sleeps through it. The trials measured something more than noise. Alcohol made breathing stop or go shallow more often, made each of those events last longer, and lowered the oxygen in people’s blood.
What we’d do
If you snore or have sleep apnea, the nightcap costs you the most, so keep drinks early and few and let them clear before bed. If someone sees you stop breathing in your sleep, or you wake up gasping, tell your doctor.
Why alcohol changes your breathing
The researchers describe alcohol as a muscle relaxant. Your airway in sleep is a soft tube that the muscles around it keep open. Relax those muscles and the tube narrows and flutters more easily, which is the sound of snoring and, when it closes, a pause in breathing.
What the trials found
The 2018 analysis pooled 14 randomized studies with 422 people, about 72% of them men, who were measured in sleep with and without alcohol.
| Who | Extra breathing pauses or shallow breaths an hour |
|---|---|
| Everyone | about 2.3 |
| People who snore | about 4.2 |
| People with sleep apnea | about 7.1 |
Alcohol also lowered average blood oxygen during sleep by about 0.6 points and the lowest oxygen of the night by about 1.25 points, and each event lasted almost a second longer. The authors call alcohol a changeable risk factor that can bring on sleep apnea or make it worse.
Sleep doctors count those pauses and shallow breaths an hour to grade sleep apnea, so the same drinks hit hardest in the people who start with the most.
Does timing help?
The trials gave alcohol before bed and didn’t track the effect hour by hour. What we know is when the alcohol is there. A drink with dinner is mostly gone by bedtime for many people, and a nightcap is still in your blood for the first hours of sleep. Your liver clears a fixed amount an hour, about 15 mg per 100 mL on average, according to a 2010 review, so moving drinks earlier is the simplest change to try. The calculator below shows when your drinks clear for your body and bedtime.
Breathing pauses aren’t the only thing that breaks up a drinking night. A 2013 review found the second half of sleep gets more broken at every dose, which why do I wake up at 3am after drinking explains.
When will tonight's drinks clear?
Bed at 11:00pm
Mostly cleared by 2:50am
That's about 3.8 hours of your sleep with alcohol in your blood (3.1 to 4.9 if your liver runs faster or slower).
Restaurant pour6 oz, 13.5%, 1.35 US drinks- Restaurant pour6 oz, 13.5%, 1.35 US drinks
REM: More REM lost. Your evening is 0.56 g of alcohol per kg of body weight.
The full clock, with the band, the same drinks two hours earlier and what your heart does.
3 sources
- Kolla BP and others, The impact of alcohol on breathing parameters during sleep: a systematic review and meta-analysis, Sleep Medicine Reviews, 2018pubmed.ncbi.nlm.nih.gov
- Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB, Alcohol and sleep I: effects on normal sleep, Alcoholism: Clinical and Experimental Research, 2013pubmed.ncbi.nlm.nih.gov
- Jones AW, Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework, Forensic Science International, 2010pubmed.ncbi.nlm.nih.gov
