Nocturia (peeing at night)
DO YOU GET UP TO PEE AT NIGHT A LOT?
WHAT’S UP WITH THAT?
The medical term for getting up to pee at night is NOCTURIA. As I mentioned in a previous post about lower urinary tract symptoms (LUTS), nocturia is the most difficult LUT to treat, because it is the most multifactorial (not just caused by an enlarged prostate, BPH). Sure, in some cases it is simply related to BPH. In these cases, symptoms should improve with medicines typically used to treat LUTS from BPH. These cases are easy to treat. But often nocturia does not get better with standard BPH treatments. These cases are more difficult, and it is important to consider other causes for nocturia.
WHEN SHOULD YOUR DOCTOR SUSPECT THAT YOUR NOCTURIA IS NOT SIMPLY A BPH PROBLEM?
1) If your symptoms only occur at night. If you have no frequency, urgency, or stream issues during the day, it makes little sense that BPH is causing your nocturia. Your prostate does not grow at night and shrink during the day.
2) Medications used to treat BPH symptoms (alpha-blockers such as tamsulosin) don’t help at all.
3) You are a very light sleeper or have sleeping problems.
4) You snore a lot, and may have untreated sleep apnea.
5) You drink a lot prior to bedtime (alcohol or otherwise).
6) You collect a lot of fluids in your legs during the daytime, causing leg swelling (AKA lower extremity edema).
OKAY, LETS EXPAND ON THAT.
Have you ever noticed that if you wake up at night, you can’t go back to sleep until you get up to pee? In most of these cases, you didn’t wake up BECAUSE you had to pee. But when you do wake up, you are often very sensitive to a small amount of urine in your bladder and “you might as well just go pee”. This often results in a very unsatisfying urinary experience, with a small volume and a weak flow.
For example, years of being on call and listening for a pager to beep has made me a ridiculously light sleeper. Anything wakes me up. When my wife’s dog was sick and sleeping in our room panting all night it woke me up hourly. I was getting up to pee 8 times a night. It would have been easy to conclude that I had a massive prostate problem. But guess what. When we put Hershey in the garage, I got up maybe once a night. It’s not uncommon that in patients like me the best treatment is to address the sleep problems rather than the prostate.
Important disclaimer: Sometimes sleeping problems may be because your spouse snores. DO NOT try to put your spouse in the garage.
On a similar note, one of the more common causes of nocturia is obstructive sleep apnea (OSA). OSA occurs when a person stops breathing during sleep, causing him to wake up. This usually occurs in people who snore, and more often in overweight patients. All of the medications in the world are not going to fix nocturia in a person with untreated OSA. Treatment of the OSA is the only solution, and often eliminates the nocturia completely.
ARE YOUR KIDNEYS JUST PUMPING OUT A LOT OF URINE AT NIGHT?
Possibly. This is called NOCTURNAL POLYURIA.
Here is how a person’s urinary tract works in a nutshell: First, blood flows through the kidneys. The kidneys filter out toxins and excess fluids and make urine. When the kidneys see more blood volume due to a well hydrated state, they make more urine. The urine then flows immediately down the ureters into the bladder, where urine is stored. Most healthy bladders store 300-400 mL of urine before you get an urge to pee. Now, a reasonably well hydrated person’s kidneys make about 100 mL per hour. For you math majors it is therefore expected that a hydrated person has to pee every 3-4 hours. Indeed, most people pee 5-7 times in 24 hours.
Okay, what happens if you pound a big glass of water before bedtime, like my wife does? Well, your kidneys make more urine and your bladder fills more frequently. Your kidneys and bladder are then just doing their jobs if you are waking up to pee. The alternative is to wet the bed.
Alcohol is a triple whammy. First, there is water in it. Its not the best way to hydrate, but it does temporarily hydrate you. Second, it is a diuretic, meaning it tells your kidneys to make even more urine. Third, it disturbs sleep patterns, unless you drink so much that you pass out. On a related note, early in my career I saw a college girl who came in for bed-wetting that started upon enrolling at C of C. Upon further questioning, she admitted that it only happened when she drank until she passed out. So…pretty obvious (“obvi” as she called it) fix there.
Bottom line is for certain people, a reasonable approach to nocturia is to limit evening fluid and/or alcohol intake.
An interesting and more subtle case is that of patients with lower extremity edema, usually from cardiovascular disease. In case you’ve heard it in Grey’s Anatomy, doctors like to call edema like this “third spacing”. The fluid collected in the lower legs during the day goes back into the blood stream when the person lays flat to sleep. In medicine this process is referred to as “mobilization” of fluids. This causes a big increase in urine production at night. These patients report that they got up a lot to pee and that their lower extremity edema also went away while sleeping. Treatments for nocturia from this cause include elevation of legs during day, compression stockings, or even taking a diuretic such as furosemide each morning.
Other diseases, most notably uncontrolled diabetes, can also cause nocturnal polyuria.
IN CONCLUSION, NOCTURIA IS TRICKY. THE PROSTATE IS UNFAIRLY BLAMED IN MANY CASES. IF IT DOESN’T IMPROVE WITH SIMPLE UROLOGIC INTERVENTION, IT’S TIME TO CONSIDER OTHER CAUSES!