Nocturia: when and how to treat it

We have seen that a healthy person does not pass urine during sleep: there is a last void before falling asleep and a first void on waking up.

Nocturia is the need to wake up one or more times during the night's sleep to pass urine, when each void is preceded and followed by sleep. Once a night is common and usually not very bothersome; twice or more starts to disturb sleep and quality of life.

Why it happens

The causes fall into four mechanisms, which are often present together:

• too much urine is produced at night (nocturnal polyuria): fluids, alcohol or coffee in the evening, swollen legs that ‘drain’ when you lie down, heart failure, sleep apnoea, reduced night-time release of antidiuretic hormone with age
• too much urine is produced over the whole 24 hours (global polyuria): drinking a lot, diabetes mellitus or diabetes insipidus
• the bladder holds less: prostatic obstruction, overactive bladder, infections, stones, neurogenic bladder
• poor sleep: insomnia, anxiety, pain; you wake up for other reasons and then go to the toilet

Why it should not be ignored

Broken sleep leads to tiredness and poorer concentration during the day. In older people, getting up at night, perhaps in the dark, increases the risk of falls and fractures.

What to do

1. Keep a voiding diary for 3-4 days: it is the starting point for understanding which mechanism predominates.
2. Cut down on fluids, coffee, tea and alcohol in the evening, but without drinking less over the day as a whole.
3. If your legs swell, keep them raised for a while in the afternoon.
4. Empty your bladder just before going to bed.
5. Talk to a urologist: treatment depends on the cause and may target the prostate, the bladder, night-time urine production or sleep.