Polyuria is a medical term for an increase in urine volume. It should not be confused with pollakiuria, a symptom characterized by frequent urination. During polyuria, the urine volume eliminated daily is greater than 3 liters.

What does polyuropolydispsic syndrome correspond to?

We speak of polyuropolydipsic syndrome when polyuria is associated with polydipsia. This symptom indicates a feeling of permanent and intense thirst. This sensation is such that the volume of water ingested daily is greater than 3 liters.

In addition to polyuria and polydipsia, polyuropolydispsic syndrome may be accompanied by other symptoms such as:

• pain or discomfort when urinating;
• a frequent and urgent need to urinate (usually more than 8 times in 24 hours);
• the presence of blood in the urine;
• fever ;
• a deterioration of the general condition;
• weight loss.

What are the different types of polyuria?

When a polyuropolydipsic syndrome is observed, polyuria can be considered as:

• primary polyuria, or primary polyuria, when it constitutes the first clinical manifestation of the syndrome and causes a so-called secondary polydipsia;
• secondary polyuria, when it is the consequence of a so-called primary polydipsia.

There is also a special case: nocturnal polyuria. By definition, this occurs at night and is accompanied by nocturia, a significant and abnormal urination occurring at night.

Polyuria can have several explanations:

• primary polydispsy, in the context of polyuropolydipsic syndrome, with excessive absorption of fluid;
• osmotic diuresis, which is characterized by an increase in urinary elimination linked to greater filtration of the blood in the kidneys;
• poor water reabsorption, due to an abnormality in the renal tube.

Secondary polyuria, the consequence of primary polydipsia

Polyuria are said to be secondary when they are the consequence of primary polydipsia. These include in particular:

• psychogenic polydipsia which is caused by psychological disorders;
• dipsogenic diabetes insipidus, which is linked to an abnormality in the control of the sensation of thirst.

Primary polyuria? Under the effect of osmotic diuresis

Primary polyuria may be due to osmotic diuresis. The increase in urine volume is the consequence of significant blood filtration by the glomeruli of the kidney. This phenomenon can occur as a reaction to:

• un diabetic sugar uncontrolled ;
• a renal failure chronic ;
• medical treatment, especially during the use of diuretics or the administration of certain saline solutions by infusion;
• parenteral tube feeding, i.e. the administration of the nutritional preparation directly into the stomach or small intestine, with protein supplementation.

Primary polyuria in? reaction to poor water reabsorption

Primary polyuria can also be linked to poor reabsorption of water from the renal tube. This anomaly is due to a alteration of the hormonal activity of vasopressin. Also called antidiuretic hormone, the latter helps control the water concentration in the body by promoting water reabsorption in the kidneys.

The hormonal activity of vasopressin may be affected by:

• central diabetes insipidus, which is caused by damage to the hypothalamic-pituitary structures within the brain, and which induces insufficient secretion of vasopressin;
• nephrogenic diabetes insipidus, which is caused by damage to certain renal structures, and which results in total or partial loss of renal sensitivity to the effects of antidiuretic hormone.

The consequences and the course of polyuria vary from case to case. The increase in urine volume often causes discomfort in everyday life. During nocturnal polyuria, the duration and quality of sleep are impacted. In some cases, nocturnal polyuria can cause urinary incontinence, that is, uncontrollable loss of urine.

The treatment of polyuria depends on its origin, its course and the patient’s condition. It may in particular be based on:

• drug treatment, especially in the context of diabetes;
• nephrology care, in case of kidney problem;
• treatment in neurology, in case of cerebral disorders;
• psychiatric follow-up, in case of psychological disorders.