Frequent urination at night: is it always the prostate?

Getting up to urinate once a night is common and doesn't usually bother people; frequent urination at night, two or more times every night, starts to affect your rest. Doctors call this nocturia. Many men immediately put it down to the prostate, but women get it too and it has other very common causes: what you drink in the afternoon and evening, some medicines, how you sleep, or conditions such as diabetes or heart failure.

What exactly is nocturia?

We talk about nocturia when you wake up during your hours of sleep because you need to urinate. The trip to the toilet before going to bed and the first one when you get up in the morning don't count.

What matters isn't just the number, but how much it affects you. Waking up several times breaks up your sleep, leaves you tired the next day and, in older people, increases the risk of falls on those night-time trips in the dark.

Why you get up to urinate at night: three explanations

Almost all cases fit one of these mechanisms, or a mixture of them.

You produce too much urine at night

This is very common in older people, and in these cases the prostate isn't to blame.

• Drinking a lot late in the day, especially coffee, tea, caffeinated fizzy drinks or alcohol, which increase urine production.
• Diuretics taken in the afternoon or evening.
• Legs that swell during the day: when you lie down, that fluid returns to the circulation and the kidneys get rid of it in the early hours. This happens with vein problems and with heart failure.
• Sleep apnoea: the pauses in breathing disturb hormonal signals and the kidneys produce more urine at night. We cover this in the article on sleep apnoea.
• Age: over the years the rhythm of some hormones changes and you urinate more at night than when you were young.

You produce too much urine all day

If you also urinate a lot during the day and are very thirsty, poorly controlled diabetes needs to be considered, along with drinking too much out of habit or, less often, other hormonal or calcium disorders. A blood test usually clears this up.

Your bladder holds less

• In men, benign enlargement of the prostate makes it harder to empty the bladder properly, so it fills up again sooner. It often comes with a weak stream, dribbling at the end or the feeling of not having finished. We explain this on the prostate check-up page.
• In men and women, an overactive bladder causes sudden, intense urges to urinate, day and night, sometimes with leaks.
• A urine infection, which usually also causes stinging and urgency.

And sometimes it happens the other way round: you don't wake up because you need to urinate, but go to the toilet because you have woken up with insomnia, pain or snoring. Explaining it this way at your appointment changes the approach.

The bladder diary: simple and very revealing

Before thinking about other tests, you will often be asked to keep a three-day bladder diary, a record of when you urinate and how much. It involves writing down:

• The time you go to bed and the time you get up.
• Every time you urinate, with the time and the amount, measured with a measuring jug.
• What you drink, how much and at what time.
• Whether you had any urgency or leaks.

These details show whether the problem is one of quantity (a lot of urine at night or all day) or of capacity (many times, but small amounts). As a guide, in older people it is considered too much night-time urine when more than a third of the whole day's urine is produced during sleeping hours, counting the first of the morning. It is the same tool used to investigate urine leaks.

What is looked at during your appointment

As well as the diary, the usual approach is to go over your symptoms, your medication, any other conditions and how you sleep, and to carry out an examination and a urine test. Depending on the case, this may be followed by a blood test for glucose and kidney function, a PSA test in men (a blood test related to the prostate) and an ultrasound scan to look at the prostate and check whether the bladder empties properly. If snoring or pauses in your sleep point to apnoea, you may need a sleep study.

Simple steps you can try

• Spread out what you drink: more in the morning and at midday, less in the two hours before bed. Don't cut your total for the day unless your doctor has told you to.
• Keep coffee, tea and alcohol for the first part of the day.
• Urinate just before going to bed.
• If you take diuretics, ask your doctor whether you can take them in the morning. Don't change how you take them on your own initiative.
• If your legs swell, ask what would suit you: raising them for a while in the afternoon sometimes helps.

If these changes don't help, treatment depends on the cause: treating the prostate or an overactive bladder, controlling diabetes, adjusting your medication or treating apnoea.

When to see a doctor without waiting

• Blood in your urine.
• Stinging, pain when urinating or a fever.
• Great thirst, large amounts of urine and unexplained weight loss.
• Swollen legs with shortness of breath, especially if you get breathless when lying down.
• Loud snoring with pauses, or great sleepiness during the day.

If you can't urinate at all and your bladder feels full and painful, go to the emergency department or call 112: it may be urinary retention, which needs immediate attention.

If getting up at night is costing you your rest, the urology clinic is a good place to start to find out whether it is your prostate, your bladder or something that can be sorted out elsewhere.