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My partner says he wakes up in the night as he needs to urinate. But could it be he needs to urinate because he has woken up?
Emily Henderson
University of Bristol, UK
You are both correct! At night, the brain and bladder debate whether to get you up to pass urine or to let you rest. Most of the time, the bladder calls the shots. As urine accumulates, stretch receptors send signals to the brain, and once the message is strong enough, you wake. If this happens more than once a night, it is called “nocturia”.
Nocturia can be triggered by all sorts of things. Hormone changes can cause the kidneys to produce more urine at night. Fluid retained in the body during the day can shift when you lie down, thereby filling the bladder. Disorders of the urinary tract or prostate can also play a role.
Beyond that, medical conditions affecting sleep, the heart, the kidneys or the hormones – as well as certain medications – can all have an impact. But the urinary system isn’t just plumbing. Behavioural cues matter too. You might have noticed how the sound of running water makes you want to go? These learned associations are examples of the brain triggering bladder action.
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At night, the brain and the bladder debate whether to get you up or let you rest. Most of the time, the bladder calls the shots
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Stefan Badham
Portsmouth, Hampshire, UK
Being an insomniac, I wake up, on average, around 20 to 30 times every night. If waking up triggered a need to urinate, then I would have to do it every time I woke up, which I don’t. However, a need to urinate always wakes me up. And thank goodness it does.
Tony Green
Ipswich, Suffolk, UK
I frequently find myself dreaming that I am urinating, but no matter how much I do so in real life, the dreaming-me keeps on peeing. Fortunately, my unconscious mind has learned that it needs to wake me up and I am always desperate for a trip to the toilet when it does. A single datum, but it leaves me in no doubt which way round cause and effect sit.
James Hardy
Belfast, UK
As a retired GP, I appreciate how urinary problems can interfere with sleep. But poor daytime choices, like excess caffeine and fluids in the latter half of the day, are surely a more common cause. In our hyperactive society, is a lot of sleep disturbance related to compulsive coffee consumption to stay awake? Adjustment of fluid intake, and wise choices on afternoon beverages, can bring welcome rest at night.
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