Is your sleep interrupted by the need to urinate, and a LOT of urine usually comes out, even if you avoid liquids for hours before bedtime? 

Sleep apnea could be the reason.

Studies linking untreated sleep apnea to having to get up in the middle of the night more than once to urinate have been around for several years.

But it isn’t just a link. There is an explanation.

There are many reasons why the urge to urinate wakes someone up more than once overnight, forcing them out of bed.

Sometimes the urine output is low, which may indicate nighttime overactive bladder, a prolapsed bladder or an enlarged prostate.

But what if you keep peeing and peeing large amounts, even though you abstain from fluids for several hours before going to bed? 

This is susepct for untreated obstructive sleep apnea.

Why does sleep apnea cause a lot of urine overnight?

This has nothing to do with the sleep apnea causing someone to wake up several times, and then — as long as they’re awake, they simply decide they may as well visit the loo.

It’s an issue of a full bladder that needs to be emptied.

When sleep apnea goes untreated, it results in more urine production. 

“While there are many mechanisms at play, the most relevant involves the production of atrial natriuretic peptide (ANP), which is a protein produced by certain muscle cells in the heart,” says Daniel Rifkin, MD, a sleep medicine expert at the Sleep Medicine Centers of Western New York.

“The exact reason why an increase in production occurs remains suspect, but an increase in intrathoracic negative pressure (trying to breathe against a closed throat creates a vacuum in your chest!) stretches some of those cells — and your heart falsely thinks that it’s due to too much blood volume.

“The frequent slowing and speeding up of your heart with apnea events also tricks the heart into thinking it’s working too hard.

“So, increasing ANP tells the kidney to diurese, or urinate, to reduce the volume.

“I tend to see this more commonly in severe sleep apnea than in the milder forms.”

A Study on Sleep Apnea and Urine

CPAP treatment reduces the frequency of nighttime urination, says a Dutch study which was presented at the European Association of Urology conference in London in the spring of 2017.

Dr. Sajjad Rahnama’l from the Maastricht University Medical Centre studied 256 patients who wore a CPAP mask for their obstructive sleep apnea.

Prior to treatment, 69 percent reported having to urinate more than once a night.

After starting CPAP, 65 percent of that 69 percent reported a reduction in peeing frequency.

When Treatments Don’t Work

If you’ve been experiencing “overactive bladder” despite a multitude of treatments (drugs, nutritional supplements, Botox injections, acupuncture, pelvic exercises), you may want to ask your doctor about the possibility of sleep apnea — even if you’re not obese.

The kidneys are supposed to be pretty much turned off during sleep so that we can get uninterrupted sleep for optimal restoration. 

Dr. Rifkin is board certified in both neurology and sleep medicine. He also treats insomnia, RLS and narcolepsy. 
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer. 
Top image: Shutterstock/cliplab
Sources: peeing overnight