When it comes to sleep hygiene, how important is uninterrupted sleep for optimal health? I have a couple of patients who continuously wake up at the same time and feel the need to use the bathroom during the night and early hours of the morning. One patient is a woman mid-20s, always finds herself waking up at 3 a.m., 5 a.m., and 6 a.m. She usually goes to bed around 11 p.m., has a history of insomnia, and problems with getting more than five hours of sleep. Water intake is fine throughout the day and not excessive during the evening. I remember hearing that our ancestors got short bouts of sleep rather than sleeping through the night and was wondering whether waking and getting up for short periods during the night had any notable negative effects on health at all. Also, why do people wake up at more or less exactly the same times despite a lack of outside influences?

Dr. Amy Nett: So this is a great question, and sleep is so individual that the answer is, as usual, it’s probably going to depend a little bit. But yeah, I think we do need some prolonged periods of sleep. So if she’s sleeping from 11 p.m. to 3 a.m., she’s really only getting about a four-hour stretch of uninterrupted sleep there; probably not ideal. And then waking up at 5 a.m. and 6 a.m., she’s probably not going to have a chance to get into the deeper stages of sleep when she only has that one- and two-hour sleeping period there. So, I mean, sometimes we see frequent urination and changes in ADH and osmolality in the setting of something like chronic inflammatory response syndrome. I mean, you could look at antidiuretic hormones if her antidiuretic hormone is particularly low. You might want to correlate that with does she have frequency of urination during the day as well, or is this just an issue at night, to see if ADH might be an issue with that. Because I think there are going to be a lot of advantages to having longer periods of uninterrupted sleep. And waking at 3, 5, and 6, you’re really not getting any; I think it’s less likely that she’s going to be getting good quality sleep from that 3 a.m. to 6 a.m. time point.

The other question though is does she wake up feeling refreshed? So does she feel tired or is she still complaining of insomnia and not feeling refreshed throughout the day?

And then you said, why do people wake up at more or less exactly the same time despite a lack of outside influences? Yeah, sometimes it is our cortisol rhythm. So it’s interesting because it sounds like you’re saying she has to go to the bathroom with each of these time points. Sometimes I think it’s more associated with a cortisol rhythm that her body gets into. So not sure if she’s, if it’s having to go to the bathroom that’s triggering her, but maybe do look into ADH, see what’s going on there.