Kidney stones

Kidney stones: description

Kidney stones are deposits that form from components of the urine. They can develop in the tubules of the kidney, in the renal pelvis and in the urinary tract. Some are only as small as rice grains, others can fill the entire renal pelvis (pouring stones).

Kidney stones are considered to be a disease of affluence: protein-rich nutrition, overeating, obesity (obesity) and lack of exercise promote kidney stone formation.

Composition of kidney stones

Depending on the composition, doctors distinguish different kidney stone types:

• Calcium containing stones: They account for 70 to 80 percent of all kidney stones. By far the most common are calcium oxalate stones, followed by calcium phosphate stones.
• Uric acid stones: Represent about 15 percent of all kidney stones, they are also called urinary stones.
• Magnesium ammonium phosphate stones: Their share is about 10 percent. Other names are Struvit or Infektsteine.
• Cystine and xanthine stones: They account for only about two percent of all kidney stones.

Kidney stones: frequency

Kidney stones are by far the most common kidney disease: About five percent of adults in Germany are affected. Mostly, kidney stones occur between the ages of 30 and 60, about twice as often in men than in women.

Kidney stones: symptoms

Read all about possible kidney stones in the article Kidney stones – Symptoms.

Kidney stones: causes and risk factors

Kidney stones are formed when certain substances are present in the urine in too high a concentration. They are initially small crystals, which continue to grow over time and join together – first forms kidney semolina, then finally kidney stones.

The causes of the supersaturation of the urine with stone-forming substances are:

• Increased excretion of stone-forming substances (such as calcium, phosphate, oxalate, uric acid) and reduced excretion of non-stone-forming substances (magnesium, citrate)
• Increased urine concentration due to dehydration and dehydration (profuse sweating), tropical climate or chronic bowel disease
• Disorders of calcium metabolism, for example due to hyperfunction of the parathyroid glands with increased calcium excretion
• Disorders of uric acid metabolism with increased uric acid excretion, which are either based on enzyme defects, or by purine-containing diet (meat!), Alcohol abuse or disintegration of tumor tissue are favored
• Urine with a pH of less than 5.5 (for uric acid stones) or more than 7.0 (for phosphate stones)

Risk factors of kidney stone formation

Various factors favor the formation of kidney stones, including:

• Foods that deprive the body of water and supersaturate the urine with salts (such as asparagus, rhubarb)
• Urinary obstruction due to scarring, constriction or malformations in the kidneys or urinary tract
• Dietary supplements containing calcium and vitamin D.
• Certain medications such as acetolsalicylic acid (ASA), acetalsulfonamide, sulfonamides, triamterene, indinavir and extremely high doses (over 4 grams per day)
• Occurrence of kidney stones in family members
• Repeated urinary tract infections
• Too low fluid intake
• overweight

Kidney stones: examinations and diagnosis

In many cases, the patient’s medical history already indicates evidence of kidney stones. The actual diagnosis is made by the physician using imaging techniques.

A common method for the diagnosis of kidney stones is the ultrasound of the urogenital tract, often with a X-ray of kidneys, ureters and bladder combined.

Another diagnostic procedure is the Ausscheidungsurografie kidney and urinary tract with X-ray contrast agent. The administration of contrast agents is not possible without elaborate protective measures in people with contrast agent allergy or pre-existing impairment of kidney function. That’s why it’s becoming more common Spiral CT recommended a modern form of computed tomography (CT). This technique does not require contrast media and can be used as an alternative to urography.

Depending on the individual case, further investigations on renal calcification are necessary, for example a cystoscopy with X-ray imaging of the urinary tract from the bladder (retrograde ureteropyelography) or a scintigraphy (a nuclear medicine examination procedure).

additional investigations

If kidney disease is suspected, the urine is examined for blood, infections and chemical changes. At least once urine is collected over 24 hours in order to calculate the daily excretion of certain substances. Blood tests help to assess kidney function as well as to detect accompanying inflammations and possible metabolic diseases as the cause of kidney stones.

People with kidney stones should use a sieve when urinating to catch stones or parts of them when urinating. An investigation of the deposits in the laboratory can provide information about the exact cause of the stone formation. Then you can treat the kidney stones targeted, or you can specifically prevent the formation of other stones.

Kidney stones: treatment

Everything important for the treatment of kidney stones can be read in the article Kidney stones – Treatment.

Kidney stones: disease course and prognosis

Kidney stones can occur again and again. After successful treatment, 50 percent of the patients regrow within ten years. However, this high rate of relapse can be significantly reduced by good stone prophylaxis.

complications

Kidney stones, for example, can lead to inflammation of the kidney pelvis (pyelonephritis), to blood poisoning due to inflammation of the urinary tract (urosepsis) and to restrictions in the urinary tract. In very serious cases can Kidney stones cause acute renal failure.