Ginecology – Urinary tract Stones

Kidney stones

Kidney stones (nephrolithiasis) are small aggregations of mineral salts that form in the urinary tract, not only for a genetic predisposition but also because of inadequate nutrition.
The stones are deposits of hard consistency which are formed by the precipitation of mineral salts contained in urine (calcium, oxalate, phosphate and uric acid). The formation of a stone is favored by the increasing concentration of these electrolytes or by the reduction of the liquid that keeps them in solution (low volume of urine). When the salts are aggregated between them are first formed crystals, then micro-stones and finally stones that can reach the size of a golf ball. Precisely because of their shape and chemical composition the kidney stones can move from the place of origin and go to obstruct the flow of urine. This barrier , in addition to causing an intense pain, often favors the development of urinary tract infections and, if it persists for long periods, increases the chances of damage to the kidneys, until to develop progressive renal insufficiency.
Normally the urine contain macromolecular (proteic origin) and micromolecular substances such as citrate or magnesium that prevent the formation of stones, although not always such compounds are present in adequate amounts or effectively perform their function. Even mucopolysaccharides, thanks to their colloidal properties encouraging the maintenance of the salts in solution thus preventing the formation of kidney stones.

Classification of kidney stones

Based on the chemical composition are distinguished different types of stones, each of them requires a different therapeutic approach:

  • Calcium (70-80%) – Calcium oxalate (60%), calcium phosphate (10%) or both (30%)
  • Uric (5-10%) – Uric acid, urate of calcium
  • Mixed (5-10%) – Calcium oxalate, uric acid and calcium phosphate (30%)
  • Cistinic (1-2%) – Cystine
  • Infectious (10-15%) – Struvite (phosphate, ammonium, magnesium), struvite and carbonate apatite or ammonium urate, calcium phosphate.

Risk Factors

Kidney stones are fairly widespread in the population as they affect on average about 3% of people. In males aged between 20 and 40 years the incidence of disease exceeds 15% due to the simultaneous presence of multiple risk factors.
The root causes of kidney stones have not yet been fully clarified, although there are predisposing factors that significantly increase the probability of forming stones:

  • Sex – Males have a chance to triple than women the develop of urinary tract stones, probably due to a high concentration of citrate in the urine of women, directly related to the rate of estrogen
  • Poor fluid intake – A limited urine flow favors stagnation, so the precipitation of salts contained in them
  • Dehydration due to increased fluid loss (diarrhea, hyperhidrosis , etc.)
  • Age – Kidney stones are formed mainly between 20 and 40 years
  • Urine Acidity – An urinary pH less than 5
  • Family history of kidney stones – As in the case of the stones of cistinic origin in which, due to a congenital defect of the kidney, cystine, a poorly soluble aminoacid in the urine, precipitates forming crystals
  • Chronic infections of the urinary tract
  • Abuse of some drugs or salt supplements and vitamins
  • Hyperthyroidism (catabolic effect on bone tissue) and hyper-parathyroidism (increased serum calcium)
  • Inadequate diet
  • Race – Higher incidence of kidney stones in the white and asian race
  • Climate – The increased sweating during hot and dry periods, increases urine concentration and precipitation of the stones if not replenished with adequate fluid intake


The stone can obstruct the passage of urine within the same kidney or more easily in the passage between the organ of urination and the ureter, which connects the kidney to the bladder, causing pain and renal colic. Fortunately not all the stones move and cause colic. Many people, however, despite not having any symptoms present noise warning such as burning and frequent urge to urinate.
Generally renal colic cause a sudden and intense pain that appears to the flank, usually from one side, forcing the patient to bend on itself. Such pain may proceed in alternating phases decreasing intensity for a moment, and then deteriorate rapidly.
When the stone moves down the ureter closer to the bladder, may appear more symptoms such as frequent urination or burning sensation; to all these signs may be associated other disorders such as nausea, vomiting, and the presence of turbid urine, sometimes with blood and bad smell. Other times there is a total inability to deliver urine.


The diagnosis of kidney stones is done with a series of instrumental and laboratory examinations. The analysis of the urine has the purpose to seek alterations in electrolytic balance and the possible presence of traces of blood. In this way it is possible to intervene assuming a diet poor of the elements present in excess and prevent the development of stones.
Among the most common investigations then there are the X-ray and ultrasound of the abdomen showing the location of the calcareous stones as composed of radio opaque substances, while there are no distinguishable uric acid or cystinic stones. The diagnosis of kidney stones can also be confirmed with more complex investigations as the urography, which involves the injection of a contrast medium for intravenous and spiral CT, a very precise and reliable examination.

Care and treatment

In case of renal colic should be administered antispasmodic drugs that relax smooth muscles, analgesics drugs or NSAIDs to reduce pain so that stop the vicious circle of pain-spasm-pain without interfering with the maintenance of ureteral peristalsis, which is essential for the progression and spontaneous elimination of the stone. The use of antispasmodics should instead be limited to cases in which the progression of the stone, because of its size and morphology, appears extremely unlikely.
To facilitate the elimination of the kidney stone you can use the method of “shot of water” by which the patient is asked to drink quickly a liter/liter and a half of water minimally mineralized, in order to unleash a powerful urinary boost which facilitates the expulsion of the stone. Generally, if the stone has a diameter less than 4 mm in 80% of cases there is the spontaneous expulsion. It is also possible to use a variety of techniques, surgical or not, depending on the size and location of the kidney stone:

  • Extracorporeal shock wave lithotripsy
    A series of shock waves generated outside the body of the patient promote the crushing of the stone and the spontaneous elimination of small fragments. This action is indicated in case of stone of small and medium-sized (below 1.5-2 cm)
  • Urethral Endoscopic Lithotripsy
    Through a small probe inserted through urethra the stone is reached and shattered with ultrasound or laser beam.
  • Renal percutaneous lithotripsy
    It is an invasive procedure that consists in crushing the stone and extract the fragments with an instrument inserted through a small hole made ​​in the side
  • Surgical treatment
    It is necessary in extreme cases, or where previous techniques had poor results


The formation of the stones depends not only to poor nutrition but also and above all a genetic predisposition, or from a disease or disorder predisposing. For this reason, there is no precise and universal diet to prevent the formation of kidney stones but rather a series of useful recommendations to counteract the formation of kidney stones.
First of all it is essential to keep the body hydrated by taking the right amount of fluids (2-3 liters of water a day), proportionate to the tenor food, physical activity performed and health conditions. In this way, in fact, the substances present in the urine are more diluted, decreasing the possibility that precipitate and aggregate. Often, in the presence of kidney stones is advisable to prefer mineral waters or slightly mineralized in order to limit the intake of sodium and calcium. In patients with stones is also important to reduce the salt intake by replacing it with spices or with hyposodium salt; limit the intake of foods rich in oxalates and hyper-proteic, increase the consumption of fruit and vegetables and urine alkalizing foods (magnesium citrate and potassium). Among the natural remedies useful for improving the painful symptoms in patients suffering from kidney stones must remember the plants rich in mucopolysaccharides, for colloidal properties, which maintain in solution the mineral salts in the urine, and the plants with a diuretic action that can facilitate the expulsion of kidney stones among which deserve special attention Birch (Betula alba), Dandelion (Taraxacum officinale) and Bermuda grass (Triticum repens)