Sleep apnea and nocturia: why sleep apnea can make you get up to pee at night

Sleep apnea can make you wake up to pee at night. When your airway closes and you strain to breathe, the pressure changes in your chest stretch your heart, and your heart releases a hormone that tells your kidneys to make more urine. Studies have found that people with sleep apnea are more likely to have nocturia, and that CPAP often cuts the number of bathroom trips. If you get up to pee two or more times a night and also snore, it's worth asking your doctor about both.

What is nocturia?

Nocturia is waking up regularly in the night because you need to pee. Cleveland Clinic defines it as regularly waking up more than once to pee. It says most people should be able to sleep six to eight hours without getting up, though getting up once or twice can be normal.

Cleveland Clinic says nocturia is very common, especially from your 50s onward, and that it disrupts your sleep and can leave you tired. It lists many causes, including drinking a lot before bed (especially alcohol, fizzy drinks or caffeine), diuretic medicines, an enlarged prostate, pregnancy and menopause, diabetes, high blood pressure, heart failure, urinary tract infections and sleep disorders, including obstructive sleep apnea. It notes that if you have obstructive sleep apnea, not using your CPAP machine can cause nocturia.

So nocturia doesn't mean you have sleep apnea. But sleep apnea is one cause that people rarely think of, because they assume the bladder is the problem.

How does sleep apnea make you pee more at night?

Sleep apnea makes you pee more at night mainly through a heart hormone called atrial natriuretic peptide, or ANP. A 2003 review in Sleep Medicine Reviews by researchers at the University of Alabama set out the mechanism.

During an obstructive apnea, your airway is closed but your chest keeps trying to breathe in. That effort against a blocked airway creates strong negative pressure inside your chest. The review explains that this pressure stretches the heart, and the stretched heart releases ANP. ANP makes the kidneys get rid of more sodium and water. It also holds back two hormone systems that normally help you hold on to fluid overnight: vasopressin, which Cleveland Clinic describes as a hormone that helps control the amount of water in your body, and the renin-angiotensin-aldosterone system.

The authors call this nocturnal polyuria, meaning you produce a large volume of urine at night.

There's a second, simpler factor. Breathing events wake you up briefly, often many times a night. A 2023 systematic review in Sleep Medicine Reviews notes that people with sleep apnea may get up to pee because they wake easily, not only because the bladder is fuller. Once you're awake, you notice the urge and go.

What does the research show?

The research shows a fairly consistent link between sleep apnea and nocturia, and a consistent drop in bathroom trips with CPAP. Most of the studies are observational or before-and-after designs rather than randomized trials, which is why the rating here is moderate.

The hormone study

In the 2004 study published in Sleep, researchers brought 30 community-dwelling older adults with nocturia and symptoms of sleep-disordered breathing into a research center for 24 hours. Their average age was 65.5. Twenty had diagnosable sleep apnea. People with an AHI above 15 had higher total urine output and higher ANP in their blood and urine. Vasopressin excretion wasn't linked to AHI. This study supports the ANP explanation, though it was small.

How common is the overlap?

A 2020 meta-analysis in Sleep and Breathing pooled 13 studies and found sleep apnea was linked to a 41% higher risk of nocturia. People with severe sleep apnea were at high risk. In the subgroup analysis the link was statistically significant in men but not in women, and the authors called for larger studies.

In a 2020 study from the Netherlands, published in Neurourology and Urodynamics, 274 patients starting CPAP were asked how often they got up at night. Before treatment, 76.4% reported at least one trip to the bathroom a night.

Does CPAP reduce nocturia?

CPAP often reduces nocturia in people with sleep apnea. In the 2006 Israeli study in Urology, 97 people with sleep apnea recorded their night-time bathroom trips for a week before their sleep study and again after one to three months of CPAP. The average fell from 2.5 trips a night to 0.7, and 73 of the 97 reported an improvement. The drop showed up in the sleep lab too, from 1.1 trips on the diagnostic night to 0.5 on the CPAP night. The participants' average age was 55, and the more breathing disturbances they had before treatment, the more often they tended to get up, though that link was weak.

In the 2020 Dutch study, CPAP cut nighttime bathroom trips by at least one per night in 42.3% of patients. The share of people with nocturia of two or more trips a night fell from 73.0% to 51.5%. There were no statistically significant differences between men and women, and the authors reported that CPAP also improved nocturia-related quality of life. A 2015 meta-analysis of five studies with 307 patients found CPAP was linked with fewer nocturia episodes and less urine overnight, and concluded that CPAP may be an effective treatment for nocturia linked to sleep apnea. The same analysis found CPAP improved daytime sleepiness scores, a reminder that fewer bathroom trips are one part of sleeping better overall.

These studies compared people before and after treatment, without a randomized control group, so some of the improvement could have other causes. Still, the results line up with the 2003 review's conclusion that treating sleep apnea can reverse the excess urine production. The American Academy of Sleep Medicine's 2019 guideline on positive airway pressure lists nocturia among the symptoms that can impair sleep-related quality of life, and suggests PAP for adults whose sleep apnea affects their quality of life.

If you already use CPAP and still get up a lot, Cleveland Clinic's point that skipping CPAP can cause nocturia is worth noting. Using it for the whole night matters. Our guide to getting used to CPAP has tips if the mask is the problem.

What should you track before your appointment?

Tracking a few things before your appointment can help your doctor sort out the cause. Cleveland Clinic says your provider may ask when your symptoms started, how many times you get up each night, whether you pee a lot or a little each time, how much caffeine and alcohol you drink, and what medicines you take and when. It says they may ask you to keep a bladder diary of how much you drink, how often you go and at what times.

It helps to add a few sleep notes alongside the diary. Write down whether you woke up first and then noticed the urge, or woke because of it. Ask a bed partner whether they hear loud snoring, gasps or pauses in your breathing. Those details point toward or away from sleep apnea in a way that a bladder diary alone can't.

What else can help with nighttime urination?

Other steps can help alongside treating sleep apnea. Cleveland Clinic suggests:

• cutting back on fluids before bed, especially caffeine and alcohol
• taking diuretic medicines in the morning or at least six hours before bed, if your doctor agrees
• raising your legs while sitting in the evening, or wearing compression stockings, to help with fluid distribution
• pelvic floor physical therapy

Alcohol is worth a second look. Besides making you pee, it can worsen breathing during sleep, which we cover in sleep apnea and alcohol. If you have diabetes, nighttime urination can have more than one cause; see sleep apnea and diabetes.

Don't stop or move any prescribed medicine without talking to your doctor first.

When should you see a doctor?

See your doctor if you're waking more than once or twice a night to pee and it bothers you, which is Cleveland Clinic's advice. They may ask you to keep a bladder diary of how much you drink and pee, and may run urine or blood tests.

Mention your sleep too. The NHS lists loud snoring, gasping or choking noises, breathing that stops and starts, waking up a lot and feeling very tired in the day as signs of sleep apnea. If any of those sound familiar, ask whether a sleep test makes sense. Our guides to sleep apnea warning signs and the home sleep apnea test explain the next steps. Cleveland Clinic lists pregnancy as one cause of nocturia, but if you're pregnant, snoring or breathing pauses are still worth raising with your clinician.

Cleveland Clinic also advises going back to your provider if nocturia doesn't go away after treatment or gets worse. A blocked nose that never clears is worth mentioning too if you snore.

If your number came back mild, our article on mild sleep apnea explains what that means. Older adults may also find sleep apnea in older adults useful, since both nocturia and sleep apnea become more common with age.

This article is general information, not medical advice. Talk to your doctor about your own symptoms.

Read next

• Why do I wake up at 3am?
• Sleep apnea warning signs
• Mild sleep apnea: what an AHI of 5 to 14 means

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.