What is nocturia?
Nocturia is a condition that causes you to wake up during the night to urinate. This can be thought of as nocturnal urinary frequency — having to urinate more often at night. This condition becomes more common as people age and occurs in both men and women, sometimes for different reasons. It can be common for most people to wake up once during the night to urinate, but urinating more frequently may be a sign of something else going on. Nocturia can be associated with daytime urinary frequency or occur by itself. It’s important to distinguish nocturia (urinating too frequently) from polyuria (urinating too much volume).
What are the causes of nocturia?
There are many possible causes of nocturia, depending on the type. The types of nocturia include:
- Nocturnal polyuria.
- Nocturnal urinary frequency.
People with polyuria urinate >3,000mL in 24 hours. This is usually caused by there being too much water filtered by the kidneys. It can also happen if something is in the urine, pulling the extra water out, such as sugar (glucose).
The causes of polyuria can include:
- High fluid intake.
- Untreated diabetes (Type 1 and Type 2).
- Diabetes insipidus, gestational diabetes (occurs during pregnancy).
Those with nocturnal polyuria experience a high urine volume only at night. Their urine volume during the day is normal or reduced. This is usually due to fluid retention during the day that often accumulated in the feet or legs. Once you lie down to sleep, gravity no longer holds the fluid in your legs. It can re-enter your veins and be filtered by your kidneys, producing urine.
The causes of nocturnal polyuria can include:
- Congestive heart failure.
- Edema of lower extremities (swelling of the legs).
- Sleeping disorders, such as obstructive sleep apnea (breathing is interrupted or stops many times during sleep).
- Certain drugs, including diuretics (water pills), cardiac glycosides, demeclocycline, lithium, methoxyflurane, phenytoin, propoxyphene, and excessive vitamin D.
- Drinking too much fluid before bedtime, especially coffee, caffeinated beverages or alcohol.
- Having a diet that’s high in sodium.
Nocturnal urinary frequency
If you have nocturnal urinary frequency, you may urinate in small amounts or urinate more frequently. The total amount of urine produced is not elevated. This is usually due to an inability of the bladder to fully empty (this is why it fills up faster) or the inability of the bladder to fill completely before developing the urge to urinate (low bladder volume). This can also occur due to difficulty sleeping — you may wake up for one reason, but then go to the bathroom while you’re awake, which will make you think that you woke up because you had to urinate.
The causes of an inability to fully empty your bladder can include:
- Bladder obstruction.
- Benign prostatic hyperplasia (men), a non-cancerous overgrowth of the prostate that obstructs the flow of urine.
The causes of an inability of the bladder to fully fill can include:
- Bladder overactivity (bladder spasms).
- Bladder infection or recurrent urinary tract infection.
- Bladder inflammation (swelling).
- Interstitial cystitis (pain in the bladder).
- Bladder malignancy.
- Obstructive sleep apnea.
What are the symptoms of nocturia?
Normally, you should be able to sleep six to eight hours during the night without having to get up to go to the bathroom. People who have nocturia wake up more than once a night to urinate. This can cause disruptions in a normal sleep cycle.
Symptoms of nocturia can include:
- Waking up more than once a night to urinate.
- Urinating more volume (if polyuria is present).
- Fatigue, sleepiness — even after waking up. This occurs because the frequent urinations can interrupt your sleep cycle.