Frequent Urination at Night in Men Over 50: Prostate or Not?

If you are a man over 50 and getting up two or three times a night, you are in large company. In community studies, between 29 and 59 percent of men over 70 get up at least twice. And almost every one of them has been told, by a friend, an advert or his own assumption, that the cause is his prostate.

Sometimes it is. More often the prostate is one contributor among several, and the others are the reason prostate treatment so often disappoints for this particular symptom. This page is about telling the difference.

What the prostate does to night-time urination

An enlarged prostate squeezes the urethra. The bladder has to push harder, often does not empty completely, and becomes more irritable over time. With urine left behind and an irritable bladder wall, the urge comes sooner, and at night that means waking.

That is a real mechanism and it does cause nocturia. The question is how much of a given man's nocturia it explains.

What a study of 505 men found

Japanese urologists looked at 505 men newly diagnosed with symptomatic prostate enlargement. Seventy-one percent got up at least twice a night. When they looked for what predicted it, the answers were age, urgency and functional bladder capacity. Prostate size was not on the list.

They then followed men who were treated. After tamsulosin, nocturia improved in 17.9 percent. After surgery, in 32.2 percent. In both groups, nocturia was the least improved of all seven symptoms on the standard prostate questionnaire. The stream got better. The nights got better less.

The largest drug trial in the field tells the same story. In the Medical Therapy of Prostatic Symptoms study, 3,047 men were randomised to placebo, doxazosin, finasteride or both, and the drugs reduced night-time voids by less than 0.2 a night more than placebo.

Signs it is the prostate

The daytime symptoms are the giveaway. A weak stream. Waiting at the toilet for it to start. A stream that stops and starts. Dribbling at the end. Straining. The feeling you have not quite emptied, and needing to go again shortly after. If you have several of these, the prostate is very likely contributing, and treatment for it is worthwhile for those symptoms in their own right.

Small volumes at night are another sign. If a three-day bladder diary shows you passing 150 to 200 ml or less each time you get up, the bladder is filling to a smaller capacity than it should, which fits obstruction or an overactive bladder.

Signs it is not, or not only

Large volumes at night. If each night-time void is a good size and the night total is more than a third of what you pass in 24 hours, you are making too much urine overnight, and no prostate treatment changes that. Causes include age-related hormone changes, evening drinks and alcohol, swollen ankles, sleep apnoea, diabetes, heart failure and diuretics taken late in the day. Our causes article covers each one.

A good stream in the day. If urine flows well and you empty fully, an obstructing prostate is unlikely to be the main problem.

Snoring and daytime sleepiness. Sleep apnoea is common in men over 50, often unrecognised, and causes nocturia through a mechanism that has nothing to do with the bladder.

New thirst, tiredness or weight loss. These point towards blood sugar.

What a urologist or GP will check

Knowing the sequence makes the appointment more useful. Expect most of these.

A symptom questionnaire, usually the International Prostate Symptom Score. Seven questions, each scored 0 to 5, one of which is specifically about how many times you get up at night. Fill it in honestly, because the total guides treatment.

A bladder diary, if you have not brought one. Bringing a completed three-day diary to the first appointment can save weeks.

A urine test, to rule out infection, blood and sugar.

A PSA blood test, after a discussion of what it can and cannot tell you. PSA rises with prostate size, infection and cancer, and is not specific to any of them. Early prostate cancer rarely causes urinary symptoms, so nocturia on its own is not a sign of cancer, but the appointment is a reasonable moment to talk about testing.

A rectal examination to assess the size and feel of the prostate.

A bladder scan after you have passed urine, to measure how much is left behind, and sometimes a flow test, where you pass urine into a device that measures how fast it comes out.

Depending on what those show, possibly blood tests for kidney function and blood sugar, or a referral for a sleep study.

What to expect from treatment

If the prostate is the main contributor, an alpha blocker such as tamsulosin will usually improve the stream within days. Expect nocturia to improve less, and less often. A 5-alpha-reductase inhibitor such as finasteride shrinks a large prostate over six to twelve months. Procedures such as UroLift, Rezum and TURP give more complete relief of obstruction than drugs, and reduce nocturia more than drugs do, but a large share of men still get up at night afterwards.

If the diary shows high night-time urine production, the treatments that matter are different: moving fluids earlier, raising swollen legs in the late afternoon, retiming a diuretic, treating sleep apnoea, and in some cases desmopressin or a deliberately timed afternoon diuretic. Our article on nocturia treatments ranks each by its effect in trials.

Most men over 50 with nocturia have both. That is the main reason to address both, rather than assuming the prostate is the whole story and being disappointed when the stream improves and the nights do not.

The supplements question

Many men try a prostate supplement first. Two have trial evidence specifically for nocturia: rye grass pollen extract, where men were about twice as likely to report fewer night-time trips than on placebo, and pygeum, where nocturia fell by 19 percent across 18 trials. Saw palmetto, the most common ingredient in combination products, has not beaten placebo in its largest trials. None of them reduces night-time urine production, so none will help if the diary shows that is your problem.

When not to wait

See a doctor promptly for blood in the urine, pain, fever, a stream that is getting steadily weaker, or new breathlessness or ankle swelling. Go to an emergency department if you cannot pass urine at all with a full bladder. That is acute retention and it does not resolve by waiting.