Waking Up at Night to Pee (Nocturia): Causes and What's Normal

Getting up in the night to pass urine has a name, nocturia, and it is one of the most common urinary symptoms there is. Once a night is usually nothing to worry about. Twice or more, night after night, is worth understanding, because the cause is often something that can be changed, and a few days of simple records usually point to which one it is.

What counts as nocturia

The International Continence Society defines nocturia as the number of times urine is passed during your main sleep period, from falling asleep to the time you intend to get up for the day. The first episode has to be preceded by sleep, and each one followed by sleep or the intention to go back to sleep.

Two voids therefore do not count: the one just before bed, and the one when you get up in the morning. That first morning void still matters, though. Its volume belongs to the night, because the urine was made while you slept.

How many times a night is normal?

Once is common, and on its own it is not considered clinically relevant nocturia. Two or more voids a night is where the research finds a real effect on quality of life, so that is the point at which it is worth looking for a cause.

Nocturia becomes much more common with age. A review of 43 community studies found these ranges:

In other words, up to 60% of older people get up twice or more a night. Common is not the same as inevitable, though: the causes below apply at any age, and many can be treated.

The four main causes

Almost every case of nocturia comes down to one or more of four things. Telling them apart matters, because the fix for each is different.

1. Making too much urine at night

Called nocturnal polyuria. Normally the body slows urine production overnight, largely through the hormone vasopressin; a change in that daily rhythm is the main mechanism. Other contributors include a high intake of water, salt or protein, caffeine or alcohol in the evening, and swollen legs: fluid that pools in the legs during the day is reabsorbed when you lie down and turns into urine. Heart failure and some medicines, diuretics in particular, can play a part.

In a diary: normal-sized or large voids at night, and a big share of the day's urine made overnight.

2. Making too much urine over the whole day

Called 24-hour polyuria: more than 40 ml of urine per kilogram of body weight in 24 hours, which is 2,800 ml for someone weighing 70 kg. The usual reasons are drinking a lot, poorly controlled diabetes, and medicines such as diuretics or lithium.

In a diary: large volumes both day and night.

3. A bladder that holds less

Here the urine volume is normal but the bladder asks to be emptied sooner. Overactive bladder is the classic cause, and so is urine left behind after voiding, which leaves less room for the night. An enlarged prostate is often mentioned too, though whether it causes nocturia or simply occurs alongside it at the same age is still debated.

In a diary: small, frequent voids by day and by night, often with urgency.

4. Sleep problems

Anything that disturbs sleep makes you more likely to notice a partly full bladder. Obstructive sleep apnea is the one to know about: in a pooled analysis of studies, people with sleep apnea were about 40% more likely to have nocturia, with the link clearest in men.

In a diary: night voids that are not especially large, plus poor sleep, loud snoring or daytime sleepiness.

The numbers that tell the causes apart

Three days of a voiding diary with measured volumes, including your bedtime, every night void and the first void after getting up, give a clinician four numbers:

• Night-time urine volume: everything passed after falling asleep, including the first void after getting up.
• Night-time share: night-time volume divided by the 24-hour total. It is commonly flagged above about 20% in younger adults and about 33% in people over 65. These cut-offs are conventions rather than firm rules.
• 24-hour total per kilogram: above 40 ml/kg points to 24-hour polyuria.
• Nocturia index: night-time volume divided by your largest single void. Above about 1.3, the night's urine is more than your bladder comfortably holds in one go.

The same symptom, two entirely different next steps. Our guide on how to interpret a bladder diary walks through every calculation, and how much urine is normal in 24 hours gives the reference ranges.

Why it is worth sorting out

Broken sleep is the obvious cost. Nocturia is also linked with falls: in a meta-analysis of long-term studies, people with nocturia had a 20% higher risk of falling, and it has been linked with higher mortality too. The researchers rated the evidence that nocturia itself causes these outcomes as very low. It is more likely a marker of the conditions behind it, which is one more reason to find the cause.

What can help

Which of these makes a difference depends on the cause, which is why the diary comes first. Guidelines recommend lifestyle steps like these, but most have not been tested on their own in trials.

• Move your drinks earlier in the day and drink less in the hours before bed. Of the lifestyle measures, reducing evening fluids has the best evidence. Do not cut your total so far that you get dehydrated or constipated: over-restricting fluids can cause its own problems, including urinary infections.
• Cut back on caffeine and alcohol in the evening. Both may increase urine production and irritate the bladder.
• Empty your bladder just before bed.
• If your ankles swell, raise your legs above the level of your heart in the late afternoon, or wear compression stockings during the day, so the fluid leaves before bedtime. Guidelines suggest this, though the trial evidence is limited.
• If you take a water tablet (diuretic), ask your doctor whether it can be taken earlier in the day. European guidelines recommend reviewing when such medicines are taken.
• If you snore loudly or feel sleepy by day, ask about a sleep apnea assessment. Treatment improves sleep; its effect on nocturia is mixed, with before-and-after studies showing fewer night voids but a randomized trial in people over 65 finding no change.
• If night voids are small and urgent, the bladder is the target: bladder training and treatment for overactive bladder.
• Treat what is underneath, such as diabetes, heart failure or incomplete emptying.

When to see a doctor

See your doctor if you regularly get up twice or more and it bothers you. Go sooner if waking at night comes with:

• Unusual thirst, or weight loss you cannot explain
• Swollen legs, or breathlessness when you lie flat
• Loud snoring with pauses in breathing, or heavy daytime sleepiness
• Blood in your urine, pain, burning or fever
• A weak stream, or a feeling that your bladder has not emptied
• A sudden change from your usual pattern

Track three nights before your appointment

For night-time urination, a three-day bladder diary is the standard first step: European urology guidelines call a validated three-day diary mandatory when assessing nocturia in men, and NICE's guideline for women asks for at least three days. At night, record when you go to sleep, every void with its volume, and the volume of the first void after you get up, plus what you drank in the evening. Those few entries are what the calculations above are built on.

Sources: Hashim H et al., ICS report on the terminology for nocturia, Neurourol Urodyn 2019; Everaert K et al., ICS consensus on nocturia, Neurourol Urodyn 2019; Tikkinen KA et al., Eur Urol 2010; Bosch JL, Weiss JP, J Urol 2010; Zhou J et al., Sleep Breath 2020; Pesonen JS et al., J Urol 2020 (falls and fractures; mortality); Wang T et al., Int Neurourol J 2015; McMillan A et al., Lancet Respir Med 2014; Kaga K et al., Cureus 2022; NICE CG97 and NG123; EAU guidelines on non-neurogenic male LUTS.

This article is educational and does not provide medical advice, diagnosis or treatment. Talk to your doctor before changing any medication.