Infrequent urination and other symptoms: pain, fever, swelling

Among the disorders associated with urinary function, urologists pay attention to such a symptom as rare urination - a decrease in the volume of urine produced by the kidneys (diuresis) and, accordingly, a decrease in its secretion from the bladder.

This deviation is called oliguria (Greek oligos – few + uron – urine), designated by the code R34 according to ICD-10.

It is difficult to accurately determine the norm of excreted urine, because this biochemical process depends on fluid intake, physical activity and many other factors. However, the average daily urine output of a healthy adult is considered to be 1.4-1.7 liters, and the number of urinations performed during the day can vary from five to seven. And the first signs of oliguria are a decrease in these indicators by a third.

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Epidemiology

According to expert estimates from the Centers for Disease Control and Prevention (USA), oliguria affects people of all ages, but is more often detected in newborns and early childhood due to comorbid conditions and high morbidity leading to dehydration. It is diagnosed 11.5% more often in male patients.

In terms of frequency, the diagnosis of "anuria and oliguria" ranks seventh in the list of symptoms associated with urinary problems, and is in second place among the most dangerous signs of nephrological and urological diseases.

According to data published in the International Society of Nephrology, the incidence of oliguria and decreased urine output varies widely depending on the clinical situation. In North America, this symptom is recorded in approximately 1% of adult patients treated by urologists and up to 5% of those hospitalized.

Acute renal failure with oliguria is determined in almost 10% of patients in the neonatal intensive care unit, and after cardiac surgery reaches 15-30%. Moreover, more than two-thirds of patients with a history of rare urination did not meet the criteria for the level of creatinine in the blood serum. And only a decrease in urine output, which is observed in more than half of patients in critical condition, predetermined a significantly higher risk of death.

According to official statistics, in 2015 in the United States, two patients died from acute oliguria, and the fatal outcome for 683 patients with severe clinical course of the disease became inevitable due to the deterioration of the condition due to a decrease in the volume and frequency of urine excretion.

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Causes infrequent urination

Let us note right away that rare urination in the heat has nothing to do with pathology: simply, when the air temperature is too high, the body protects itself from overheating by increased sweating, and in order to prevent dehydration and disruption of water-salt homeostasis, the autonomic nervous system gives the kidneys a “command” to reduce the activity of water excretion and increase its reabsorption in the tubules.

Extrarenal oliguria is associated with such causes of rare urination as obstruction of the urinary tract - if they are partially blocked by a tumor in the bladder or kidney stones. Although, first of all, among the diseases and pathological conditions in which symptoms of rare urination appear, urologists include:

• dehydration of the body (dehydration) due to loss of fluid due to prolonged vomiting or diarrhea, as well as hyperhidrosis due to fever and infectious intoxication;
• decrease in the glomerular filtration rate in acute renal failure (hepatorenal syndrome) and chronic renal failure;
• acute tubulointerstitial nephritis;
• pyelonephritis;
• glomerulonephritis (inflammation of the renal glomeruli);
• hereditary polycystic kidney disease;
• renal amyloidosis;
• cirrhosis;
• chronic heart failure, coronary heart disease, infarction;
• myocarditis (inflammation of the heart muscle);
• severe arterial hypertension (which can lead to the development of arteriolar nephrosclerosis with partial renal dysfunction). In addition, hypertension usually accompanies acute glomerulonephritis, i.e. it can be secondary to changes in vascular tone;
• hypothyroidism or autoimmune thyroiditis;
• autoimmune disorders such as systemic lupus or Goodpasture's syndrome.

Urine output is sharply reduced in the development of conditions requiring urgent medical action: peritonitis and sepsis; cardiogenic and anaphylactic shock; hemouremic syndrome; bleeding and hypovolemic (hemorrhagic) shock.

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Risk factors

In addition to all the listed diseases, risk factors for oliguria include increased secretion of the pituitary hormone vasopressin (antidiuretic hormone, ADH) – a physiological regulator of water excretion by the kidney. Disruption of its production can occur due to damage to the hypothalamus and pituitary gland: tumor formation, craniocerebral trauma, infectious inflammation (meningitis or encephalitis), congenital anomalies (hydrocephalus, cerebellar atrophy, etc.), pathologies of the peripheral nervous system.

There is also a high probability of this urinary disorder occurring in oncological diseases affecting the lungs, thyroid gland, genitourinary organs of men and women, gastrointestinal tract and pancreas; in Ewing's sarcoma and leukemia in children and adolescents.

Diuresis may decrease when taking medications such as anticholinergic and antihypertensive agents, loop diuretics, aminoglycoside and quinolone antibiotics, nitrofuran derivatives, antitumor drugs (Methotrexate, Cisplatin, Alvocidib, etc.).

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit renal synthesis of vasodilatory prostaglandins, and their use in children with fever and intercurrent dehydration causes acute oliguria.

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Pathogenesis

With excessive secretion of ADH and, accordingly, a significant increase in its concentration in the blood plasma, diuresis in adults can decrease to 0.4-0.5 liters per day, which in many cases explains the pathogenesis of a decrease in the number of urinations.

Thus, excessive production of ADH is observed during dehydration of the body - when the volume of intercellular fluid is sharply reduced and the number of urinations decreases - in acute conditions and severe forms of diseases. The same thing happens with a sharp decrease in the volume of circulating blood (hypovolemia) - in cases of bleeding.

The synthesis of this hormone is increased in hypertension - in response to increased levels of aldosterone (adrenal cortex hormone) and angiotensin II produced by the kidneys. As part of the system that maintains water-salt balance (renin-angiotensin-aldosterone), both of these neurohormones cause water retention in the body, enhancing the antidiuretic effect of vasopressin.

In chronic heart failure and liver cirrhosis, ADH release may be the result of a so-called osmotic trigger, when neurotransmitters respond to a lack of intravascular blood volume as if it were hypovolemia.

Thyroid hormone deficiency, caused by hypothyroidism or autoimmune thyroiditis, systemically suppresses metabolism and causes infrequent urination.

And with glomerulonephritis and the initial stage of acute renal failure, the process of filtration of blood plasma by the glomeruli of the nephrons slows down, which leads to a decrease in diuresis and a reduction in the number of urinations.

In the presence of oncology, the pathogenesis of oliguria development is associated with tumor cell lysis syndrome and the release of increased amounts of potassium, phosphate, and nitrogenous bases into the blood. And then their breakdown by uric acid leads to hyperuricemia and hyperphosphatemia, as a result of which high concentrations of uric acid and calcium phosphate in the renal tubules potentiate the risk of acute kidney injury and decreased urine production.

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Symptoms infrequent urination

Among other symptoms, rare urination with edema occurs in chronic heart failure and liver cirrhosis, glomerulonephritis and kidney inflammation in children. Edema combined with oliguria, as well as increased thirst and rare urination with copious drinking may be present in the clinical symptoms of the third degree of arterial hypertension.

Edema of the renal parenchyma - with a reduction in the number of urinations, proteinuria and hematuria - is observed in cases of their amyloid dystrophy with regular hemodialysis.

In patients who have suffered acute cerebrovascular accident, rare urination after a stroke (hemorrhagic or ischemic) is part of neurological disorders. And this may be another confirmation of extensive damage to brain structures (hypothalamus, temporal and frontal zones) due to its short-term hypoxia.

Infrequent urination with pain of any localization is explained by a reflex decrease in diuresis: the sympathetic nervous system reacts to pain syndrome by releasing adrenaline and norepinephrine, which increases the level of vasopressin, which affects the formation of urine in the kidneys.

Patients with glomerulonephritis, arteriolar nephrosclerosis and polycystic kidney disease complain of infrequent urination and back pain. Impaired urine outflow from the kidneys - congenital hydronephrosis in children, as well as the development of kidney and ureter edema in pregnant women cause a decrease in urination, accompanied by pain in the back, side or abdominal cavity, as well as nausea and vomiting. Headaches and painful sensations in the abdominal region are noted with acetonemic syndrome.

Please note: brown urine and infrequent urination are a sign of fluid deficiency in the body, evidence of which is the excess content of urochrome (a substance containing bile pigments) in the urine.

Infrequent urination in a child

The normal frequency of urination in children varies widely and depends on age. Thus, most children by the age of three or four urinate about ten times a day, and teenagers - as many as adults.

But children can also suffer from oliguria. True, physiologically conditioned rare urination in a child in the first two or three days after birth is a consequence of the establishment of lactation in the mother and extrauterine digestion in the baby. But in the future, cases of decreased urination and a more saturated color of urine should not go unnoticed: this symptom can be a warning of the development of dehydration, which young children tolerate extremely hard.

Moreover, in infants, oliguria with palpable kidneys suggests renal vein thrombosis, polycystic kidney disease, multicystic dysplasia, or hydronephrosis.

Experience shows that the reasons for infrequent urination in children are basically the same as in adults, but with any infections and hyperthermia, the symptom of decreased diuresis in children is more pronounced.

According to pediatricians, this symptom most often appears in infectious diseases (including respiratory viral diseases) and acute renal failure in children.

Infrequent urination in women

In addition to the above-mentioned general reasons for infrequent urination in women, there are specific reasons – during the restructuring of the body associated with menopause and pregnancy.

Infrequent urination during pregnancy is most often observed with early toxicosis (due to frequent vomiting) and gestosis (with increased blood pressure). In addition, during the period of bearing a child, the activity of antidiuretic hormone (ADH) increases, which is facilitated by an increase in the level of the neurohormone angiotensinogen in the blood - in response to the increase in the content of female sex hormones (estrogen and estradiol) in the blood, which is natural for this condition, the receptors of which are found in the organs of the urinary system.

During menopause, oliguria is provoked by functional disorders of the autonomic nervous system, partially regulated by neurohormones of the pituitary gland and hypothalamus, as well as changes in the functioning of the endocrine system and general metabolism.

Infrequent urination in men

As a rule, infrequent urination in men is observed with kidney failure, urolithiasis, inflammatory processes in the genitourinary organs, tumors in the genitourinary system, heart problems, high blood pressure, diseases of the brain or spinal cord.

For example, rare urination with pain, cutting and spasms in the lower abdomen can be caused by narrowing of the urethra, hyperplasia, adenoma or malignant tumor of the prostate gland. However, most often in these cases ischuria is diagnosed - urinary retention due to the inability to completely empty the bladder.

Indirect factors that disrupt the normal process of urination may include alcoholism (causing cirrhosis of the liver), abuse of diuretics, intensive antibiotic therapy, nervous tension, etc.

Forms

As you have seen, a pathological reduction in the number of urinations can be caused by many reasons, and depending on the etiology, oliguria - as a symptom of urinary dysfunction - is divided into types: renal primary, renal secondary and extrarenal.

Primary renal oliguria (renal) is directly related to damage to the structure of the kidneys or ischemia of its vessels. This includes congenital pathologies and dysfunctions of the kidneys, inflammatory processes, acute tubular necrosis, primary glomerular diseases and vascular lesions (for example, arteriolar nephrosclerosis).

Secondary renal oliguria (prerenal) is a functional reaction of structurally normal kidneys to insufficient blood circulation (hypoperfusion) during bleeding, sepsis, shock conditions, dehydration (caused by vomiting, diarrhea, extensive burns), strokes, cardiovascular diseases, etc. To normalize the intravascular volume - due to the mobilization of the renin-angiotensin-aldosterone system and activation of the sympathetic nervous system - a decrease in the glomerular filtration rate occurs, reabsorption of electrolytes and water increases, and urine output decreases. It accounts for two thirds of all diagnosed cases of reduced urination in acute renal failure.

Extrarenal oliguria (postrenal) refers to infrequent urination due to mechanical or functional obstruction of urine flow in the ureter, bladder, or urethra.

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Complications and consequences

In general, prolonged urinary insufficiency and acute renal failure can have serious short-term and long-term consequences and complications. Everything depends on the etiology, age and the state of other body systems.

However, the development of acute renal failure occurs in almost two-thirds of cases, and in children under one year of age, severe acute kidney injury requiring renal replacement therapy has a very high mortality rate (up to 30%).

As a result of fluid, sodium and potassium retention in the body, there is a violation of water-electrolyte homeostasis and acid-base balance, which leads to the development of metabolic acidosis; complications of the cardiovascular system (including arterial hypertension, heart failure with arrhythmia and pulmonary edema); hematological and neurological disorders.

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Diagnostics infrequent urination

It is easy to detect such a symptom as rare urination: oliguria is defined if urine output is less than 1 ml per kilogram of body weight per hour in children and less than 0.5 ml in adults. This is one of the clinical signs of renal failure associated with reduced diuresis.

The efforts of doctors are aimed at determining the causes of this symptom, for which an examination is necessary. Blood tests are done: general, biochemical, for the level of creatinine, renin, ADH, for the presence of nephrogenic antibodies and immunoreactivity; in men - for the presence of prostate antigen.

In acute oliguria, hemodynamics with the volume of circulating blood are determined.

Urine tests are taken: general (clinical), daily, bacteriological, for sodium level, specific density and osmolality. If necessary, other laboratory tests are prescribed to clarify the diagnosis.

Instrumental diagnostics involves visualization of the relevant organs, for which ultrasound examination of the kidneys and bladder, X-ray of the urethra (urethrography) are used. The features of the bladder functioning (filling, emptying and its speed) are determined, for which uroflowmetry and cystometry are performed. In rare cases, magnetic resonance imaging with the use of a contrast agent is required.

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Differential diagnosis

Given the spectrum of diseases with this symptom, differential diagnostics can be carried out by doctors of various specializations (with additional examination). But all of the above is reduced to blood and urine tests in emergency situations.

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Treatment infrequent urination

It is a mistake to think that treatment of rare urination can only be symptomatic - with the help of diuretics; or that treatment with folk remedies will help (which in this case is unacceptable, since most of the herbs used have diuretic properties).

Urologists warn that diuretics are used to treat secondary renal oliguria (that is, caused by hypertension, heart failure or liver cirrhosis) - when the excretory function of the kidneys is not impaired, and in response to the action of the drug, they will be able to ensure plasma filtration and urine production in normal volumes.

So the etiology of this symptom and the condition of the kidneys determine the method of treating oliguria and the drugs used, and the goal of therapy is to normalize the urinary function. And in most patients, the acute condition is amenable to intensive therapy without the development of severe renal failure.

To increase diuresis in cases of secondary (prerenal) oliguria, loop diuretics Mannitol (Mannitol, Diosmol, Renitol) or Furosemide are commonly administered (by intravenous drip); the dosage is calculated based on body weight. The use of these drugs requires monitoring of serum sodium and potassium levels.

And to improve intrarenal blood circulation (if the patient does not have severe dehydration), Dopamine is also used intravenously.

To restore fluid and increase diuresis, children are given sodium chloride parenterally in the form of an isotonic solution, as well as Ringer's solution.

To increase urine volume in cases of infrequent urination with edema associated with chronic cardiac and adrenal insufficiency, hypertension or hypothyroidism, the drug Tolvaptan (an inhibitor of antidiuretic hormone), which increases the sodium level in the blood, can be used.

Prevention

The average adult excretes about 75-80% of the fluid consumed daily in urine, so the main method of preventing infrequent urination is an optimal drinking regime and control over the amount of water entering the body.

Doctors strongly advise to stop drinking alcohol, treat existing diseases and take medications only in accordance with medical recommendations.

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Forecast

To emphasize the real danger of a sharp decrease in the frequency of urination and a critical decrease in urine production by the kidneys, it is enough to note the very high percentage of fatal outcomes - in the absence of timely emergency (often resuscitation) medical care. If rare urination is left unattended, the development of this symptom can lead to a terminal condition.

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