There are normally two kidneys in humans. The kidneys are small organs which can be found behind the abdominal cavity in a space called the retroperitoneum. They are approximately at the vertebral level of T12 to L3. The kidney participates in whole-body homeostasis, excretion and releases important hormones.
Small, solid masses called kidney stones may form when salts or minerals, which are normally found in urine, become solid crystals inside the kidney. These crystals are normally too small to be become aware of, and pass harmlessly out of the body. However, they can build up inside your kidney and form much larger kidney stones. If a stone becomes large enough, it may begin to move out of the kidney and progress through the ureter (a tube that carries urine from the kidney to the bladder). A kidney stone can become stuck at various parts of the ureter or kidney causing pain, infection and occasionally kidney damage. These kidney stones can be in many different shapes and sizes.
The peak age for kidney stones is between 20 years old and 50 years old. The risk of having kidney stones in males is three to four times larger than in females. Other diseases like high blood pressure, diabetes, obesity, osteoporosis, chronic diarrhoea, or kidney cysts might increase the risk of having kidney stones as well. If the patient has previously had a kidney stone then he/she will have a 50 percent chance of developing another one within five years. A family history of kidney stones also increases the risk of developing kidney stones (cvstine stones).
Kidney stones form when there is a decrease in urine volume and/or an excess of stone-forming substances in the urine. The most common type of kidney stones present contains calcium in combination with either oxalate or phosphate. Other chemical complexes that can form kidney stones in the urinary tract include uric acid and the amino acid cystine. Dehydration from reduced fluid intake, excessive sweating, or strenuous exercise without adequate fluid replacement may lead to the formation of kidney stones. Obstruction to the flow of urine can also lead to kidney stone formation. Kidney stones can also result from infection in the urinary tract; these are known as struvite or infection stones. Ingesting too much sugar, salts, and/or protein may lead to the formation of kidney stones as well. This is due to protein containing amino acids (which includes cystine); fructose is a sugar which some individuals metabolize into oxalate. Many different medical conditions may also lead to the formation of kidney stones. These medical conditions include gout (which results in an increased amount of uric acid in the urine and can lead to the formation of uric acid stones.), Hypercalciuria (too much calcium is absorbed from food and excreted into the urine, where it may form calcium phosphate or calcium oxalate stones.), hyperparathyroidism, cystinuria and hyperoxaluria. Medication may also lead to kidney stone formation. These medications include some diuretics, some chemotherapy medicines for cancer and some medication used to treat HIV and AIDS.
The presence of kidney stones may cause the patient to have symptoms of sudden pains in their abdomen, lower back, or/and groin area. Renal colic may occur in severe cases, which is accompanied by nausea and vomiting. Kidney stones also cause blood to be present in urine; this is caused by the kidney stone rubbing with the wall of the ureter. Sometimes symptoms such as frequent urination, difficulty in urinating, and testicular pain may also occur. Fevers and chills may occur as well when the patient has kidney stones as well as an infection in the urinary tract.
The diagnosis of kidney stones is suspected by the typical pattern of symptoms when other possible causes of the abdominal or side pains are excluded. Imaging tests are usually done to confirm the diagnosis. There are 2 methods that can be used to detect kidney stones, the helical CT scan (which detects any obstruction in the urinary tract without any contrast material) and the intravenous pyelogram (IVP: an X-ray of the abdomen along with the administration of contrast dye into the bloodstream). Helical CT scans have been shown to be a significantly more effective diagnostic tool than the IVP in the diagnosis of kidney or urinary tract stones. In pregnant women or those who should avoid radiation exposure, an ultrasound examination may be done to help establish the diagnosis.
There are many methods of removing a kidney stone. Most kidney stones eventually pass through the urinary tract on their own within 48 hours, with ample fluid intake. Pain medications are used for symptom relief. For kidney stones that do not pass on their own, a procedure called extracorporeal shock wave lithotripsy is often used. In this procedure, shock waves are used to break up a large stone into smaller pieces that can then pass through the urinary system. Surgical techniques have also been developed to remove kidney stones when other treatment methods are not successful or helpful. This may be done through a small incision in the skin (percutaneous nephrolithotomy) or through an instrument known as an ureteroscope, which is passed through the urethra and bladder up into the ureter.
Rather than having to undergo treatment, it is best to avoid the formation of kidney stones in the first place when possible. It can be especially helpful to drink more water, since low fluid intake and dehydration are the major risk factors for kidney stone formation. Depending on the cause of the kidney stones and an individual’s medical history, dietary and lifestyle changes and/or medications are sometimes recommended to decrease the likelihood of developing further kidney stones.