Many people get up to pee at night.  This could simply be a reflection of drinking water before bedtime, caffeine, or alcohol, or it could be a symptom of a medical problem, one of which is sleep apnea.

Obstructive sleep apnea (OSA) is a condition where the upper airway is obstructed during sleep, causing pauses in air intake despite an effort to breathe.  The severity of OSA is determined by the number of apnea (no airflow) or hypopnea (decreased airflow) events during an hour, measured during overnight testing:

  • mild OSA: 5-15 events per hour
  • moderate OSA: 15-30 events per hour
  • severe OSA: over 30 events per hour
Obesity is a common cause of OSA, but it can also be caused by decreased muscle tone of the upper airway (due to neurologic conditions or substances such as alcohol, sedatives, or muscle relaxants), or variance in the structure of the upper airway.
So how does OSA cause a person to pee excessively at night?  Research has shown us that the negative pressures generated in the chest by trying to inhale against a blocked airway cause increased blood return to the right side of the heart.  This, in combination with other pressures placed on the heart by OSA, cause the heart to release a hormone called atrial natriuretic peptide (ANP) that tells our kidneys to excrete more sodium and water.
Other common symptoms of OSA include daytime sleepiness, morning headaches, difficulty concentrating, restless sleep, and snoring. OSA is not thought of or tested for enough, and as a result, many people suffer from OSA but don’t know that they have it.
There are many other medical problems that can cause a person to pee at night, ranging from bladder issues, to prostate problems, to uncontrolled diabetes, to congestive heart failure, to several others.   For health care providers, it’s important to consider obstructive sleep apnea on this list when a patient tells us they are urinating often at night.   If you are a patient urinating excessively at night, be sure to speak to your doctor about it.


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