Polyuria and frequent urination

Polyuria - diuresis more than 3 l / day; it should be distinguished from increased urination, which is the need to urinate many times during the day or night, but in normal or less than normal volumes. Each of the symptoms may include nocturia.

[1], [2]

Causes of the frequent urination

Polyuria means diuresis of solutes or water. Causes of water diuresis include central or nephrogenic diabetes insipidus, psychogenic polydipsia, and infusion of hypotonic solutions.

Causes of solute diuresis include diabetes mellitus, saline infusions, tube feeding with mixtures containing large amounts of protein, resolution of urinary obstruction and nephropathy when sodium is depleted.

The most common urologic causes of increased urination include UTI, urinary incontinence, BPH, and urinary calculi.

[3], [4], [5], [6], [7]

Diagnostics of the frequent urination

Anamnesis can help differentiate polyuria from increased urination and indicate a possible cause. Polyuria caused by diabetes insipidus is suggested based on the history of a malignant neoplasm or chronic granulomatous disease (through hypercalcemia), the use of certain drugs (lithium salts, cidofovir, foscarnet sodium) and less common disorders (for example, sickle cell anemia, kidney amyloidosis. Sjogren syndrome), whose manifestations are often more pronounced than polyuria, and precede it.

Acute onset of polyuria at the exact time suggests central diabetes insipidus. Polyuria caused by diuresis is assumed based on a history of diuretic or diabetes mellitus, and polyuria caused by polydipsia is based on a history of mental illness (bipolar affective disorder, schizophrenia).

Dysuria involves increased urination due to UTI or calculi. Previous surgery on the pelvic organs involves incontinence, and the weakening of the urine stream - BPH.

Physical research as a whole plays a limited role in the evaluation of polyuria and increased urination.

[8], [9], [10], [11]

Polyuria screening

Measurement of urine volume in 24 hours allows differentiation of polyuria (> 3 l / day) from increased urination, if this difference is not evident on the basis of history. The allocation of more than 5 l / day involves central diabetes insipidus, lithium intoxication or polydipsia.

Urinalysis should be performed to detect UTI or glycosuria. Examination of serum sodium can distinguish polydipsia (sodium <137 mEq / l) from non-sugar diabetes (sodium> 142 mEq / l). The diagnosis of diabetes mellitus is established under the condition that drinking water is completely restricted, based on the measurement of the volume and osmolarity of urine, osmolarity and sodium concentration of blood plasma.

[12], [13], [14], [15]

Treatment of the frequent urination

Treatment of polyuria and frequent urination depends on the cause.