Stone disease: background of stone formation

Stone-forming substances normally excreted in the urine
Urinary stones consist of 90 percent from crystals and only 10 percent of organic material. The substances involved in stone formation are, in every person in dissolved form in the urine. These are calcium oxalate, calcium phosphate, magnesium ammonium phosphate (struvite), uric acid or cystine. These substances are also known as lithogenic (stone-forming) agents. They are normally excreted in the urine. But the concentrations of individual substances exceed certain limits, are formed from crystals. Combine several crystals of this state and takes a long time, so eventually form stones.


Every person has substances that inhibit stone formation and promote. In healthy people they are in equilibrium
Every person has in his body on crystallization suppressive substances that are normally in equilibrium with the stone-forming substances be excreted in urine and crystallization-promoting substances in the body. Crystallization suppressing substances are also known as inhibitors (inhibitors). They provide to healthy people that are the focus in the urine and the substances do not crystallize, but are excreted normally. Some of these substances:

    Citrate
    Magnesium
    Glycoproteins
    Pyrophosphate
    Nephrokalzin
    Glycosaminoglycan

A lack of inhibitors supports the formation of crystals. The effectiveness of inhibitors is also dependent on urinary pH and ionic strength of the stone-forming substances and their concentration.


Various diseases and food and nutrition habits conducive to stone formation
The stone formation is favored by several factors. The risk factors include inter alia:

    Family history
    Lifestyles and eating habits such as lack of exercise, immobilization: immobility and / or bed rest as after bone fracture, inadequate fluid intake, excessive sweating, over-consumption as of meat
    Drugs, such as calcium, vitamin C, vitamin D therapy

Also favoring diabetes mellitus act, gout, kidney disease, hyperparathyroidism (overactive parathyroid gland) or malignant tumors. Urinary stones in these diseases often occur as a side effect, because they bring metabolic changes.

 
The research has still not 100% statement
This theory of stone formation provides the basis for treatment and diagnosis of urolithiasis. It is insufficient in some cases. Exactly is still not proven why someone eventually develops kidney stones. Because even make healthy people, without them complaining of discomfort, urinary stones. This will leave an even smaller form. In addition, some types of stones grow so slowly that they would be washed away without obstacles in the urine in a natural way.


Calcium and Okalatsteine ​​arise already in the renal tissue
The result is the most common types of stone, calcium oxalate stones and even within the kidney tissue. As a formation mechanism is believed to die because of degenerative or kidney-damaging diseases and individual kidney cells calcify. At these then form within the kidney stones. Only then dissolve the dead cells and kidney stones with them, the educated and inhibit the urine flow.


The stone formation is multifactorial
But this allows the origin does not explain most types of stone. So as to form not only exceeding a certain concentration or kidney damage the "cornerstone" of stone disease. Only an interplay of many factors ultimately leads to stone formation. The disease is therefore often referred to as multifactorial. Total is less than 10 percent of cases a clear defined - usually nichtnephrologisches problem - the underlying urolithiasis.