One in three North American adults have to get up to urinate more than twice a night, and a study presented at the European Society of Urology shows that the most common cause may be taking in too much salt (International Journal of Urology, Mar 14, 2017;24(3)). Instead of this obvious cause, many urologists concentrate on treating night-time urination primarily as Lower Urinary Tract (LUTS) obstruction (Can Urol Assoc J. 2012 Oct; 6(5 Suppl 2): S138–S140). The treatments they offer include:
• Surgery that decreases night-time urination an insignificant amount, from 3.4 times a night to 2.6 (Urology, 2007;70:493–7).
• Indiscriminate use of drugs almost never offer a cure. The most commonly used drugs such as alpha-blockers, anti-muscarinics, and 5-alpha reductase antagonists lose their benefit over time (J Urol, 2003;170:145–8; Eur Urol Suppl, 2005;4:61–8;J Urol, 2007;178:2045–51; BJU Int, 2007;100:579–87; Int Urogynecol J Pelvic Floor Dysfunct, 2007;18:737–41; BJU Int, 2006;97:1262–6; Urology, 2006;67:731–6; JAMA, 2006;296:2319–28).
The higher the salt intake, the more the people urinated day and night and the higher their blood pressures. Japanese researchers proved how much salt 728 night-time urinating people were taking by repeatedly measuring the amount of salt that they put out in their urine. The average salt intake for the entire group was 9.2 grams per day. The patients were divided into two groups: those above and below the mean salt intake of 9.2 g/day. All were taught how to follow a low-salt diet. After 12 weeks, more than 200 people in the study reduced their salt intake from an average of 11 grams per day to 8 grams a day and they also reduced their night-time bathroom trips from 2.3 to 1.4 times per night. The 100 patients whose average-salt intake increased from 9.6 grams per night to 11 grams nightly also increased their night-time urination from 2.3 to 2.7 times a night.
In another study, salt loading (0.5 g salt per 10 Kg of weight) for just one night markedly increased night-time urination in normal healthy males (Pak J Physiol, 2014;10(3-4):6–9).
How Much Salt Is Healthful?
The American Heart Association recommends that people consume no more than a teaspoon of salt per day (2,300 milligrams). Since both high salt and low salt intakes can cause high blood pressure, everyone needs some salt. However, most healthy North Americans do not need to use a salt shaker because they eat so much processed foods that have extra salt added.
Night-Time Urination is a Generalized Disorder
Most patients with excess night-time urination are referred to urologists who rarely do medical evaluations for the most common causes (Can Urol Assoc J, 2012 Oct; 6(5 Suppl 2); BJU Int, 2002;90(Suppl3):28–31). They should be evaluated for:
• urinary tract infections
• high blood pressure
• heart disease
• congestive heart failure
• blocked blood vessels
• restless leg syndrome
• hormone disorders such as lack of the brain anti-diuretic hormone (treated with the drug, Desmopressin)
• kidney damage
• excess accumulation of fluid in the legs
• obstructive sleep apnea
• side effects of drugs such as steroids, blood pressure medication or diuretics,
If none of these causes is found, the patient may be helped by:
• not eating or drinking after 6PM
• restricting alcohol and caffeine
• treating swollen legs with compression, elevation and possibly morning use of diuretics
• treating sleep apnea with nasal continuous positive airway pressure
• People who suffer frequent night-time urination should receive a medical examination for the most common causes.
• Urinary tract infections usually can be cured without surgery.
• Night-time urination should also be checked by a urologist for bladder and prostate disease.
• The commonly-used drugs (alpha-blockers, anti-muscarinics, and 5-alpha reductase antagonists) will not cure you. Expect these drugs to lose their beneficial effects as you continue to take them.
• If a medical evaluation fails to find a cause, you may get better just by restricting your intake of salt.
• Salt restriction can harm someone who lacks the brain hormone that controls urination, so people with night-time urination should be checked for blood levels of salt (sodium) and a night-water restriction test to measure the specific gravity of their urine.