The symptoms are intense and frightening. Kidney stones are insidious, building over a long period of time without any symptoms, only making themselves known when the body tries to purge them.
A kidney stone, or renal lithiasis, is a hard mass made up of tiny crystals that separate from a person's urine. These crystals collect in the urinary tract, taking several weeks, months, or even years to form. A kidney stone can lay dormant in the kidneys for a long period of time, undetected. Normally, they are only detected when a patient receives an X-ray for another matter, or when the stone begins to move out of the kidneys.
Doctors do not know definitively what causes kidney stones to form, although patients who suffer from multiple cases can follow preventative measures based on the type of stone that tends to form in their kidneys. There are four main kinds of kidney stones, classified by the material of which they are made: calcium, cystine, struvite and uric.
Most common are calcium stones, affecting men in their 20's to 30's predominantly. These form when excess calcium in the urine combines with oxalate (present in certain foods such as spinach and in vitamin C supplements), phosphate, or carbonate, forming a stone. Those with intestinal disorders are more prone to calcium stones.
Cystine stones are common among those with cystinuria, a medical condition in which an amino acid named cysteine forms stones in the kidneys. Cystinuria is hereditary. In those without this condition, cysteine breaks down in the kidneys and returns to the bloodstream. Someone with this disorder finds the cysteine instead collecting and forming crystals, which then coalesce into stones.
Struvite stones are found mostly in women who suffer from urinary tract infections. Struvite is a natural compound found in the urine and can be extracted from waste water for use as a fertilizer due to a high phosphorous content. Struvite stones can grow very large, causing a painful and dangerous blockage in the urinary tract.
Lastly are uric acid stones. Uric acid is a waste product that develops from the breakdown of numerous kinds of foods. In most cases, uric acid is lost through urination. People suffering from gout of receiving chemotherapy, however, may not be able to properly process uric acid, leading to the formation of stones in the kidneys.
Each year, approximately 3 million people will receive treatment for kidney stones. These generally only cause pain when they attempt to leave the kidneys and pass through the urinary tract, beginning with the ureters. The ureters are the narrow tubes that connect the kidneys to the bladder. Smaller stones may pass through the ureters without being felt. In fact, many people pass kidney stones completely without realizing they have done so, if the stones are small enough. Stones too large to pass through the ureters may require medical treatment or even surgery to remove.
Most times, kidney stones are felt when they enter the urethra, the very small passage leading from the bladder to the outside of the body. Detecting kidney stones can be difficult due to their small size. A physician may order a blood or urine test to check for blood or minerals such as calcium in the body. Alternately, an X-ray or similar scan may be used, especially if it is suspected that a stone is still in the kidney.
Treatment for kidney stones varies, depending on the type and size of the stone. For smaller stones, no treatment may be necessary. The patient may be advised to simply drink lots of water to “flush” the stone from the body, utilizing pain relievers to dull the symptoms. For larger stones, ones causing damage and bleeding, or patients with severe urinary tract infections, there are several options.
If the stone is in the kidney or ureter, surgery may be necessary. This involves making a small incision in the lower back to physically remove the stone. Once a common procedure for removal of larger stones, surgery is now used only if other treatments prove ineffective. First, a physician may try using sound waves to break the stone into smaller pieces. This is called extracorporeal shock wave lithotripsy, using sound waves to create small shock waves that damage the stone, breaking it into easily-passed pieces.
Alternately, a ureteroscope can be inserted into the urinary tract to physically remove a stone from the ureter or kidney. The ureteroscope has a camera attached, allowing the physician to locate and remove the stone with ease.
Even more important than treatment is prevention. Doctors recommend several lifestyle changes for those suffering from multiple kidney stones. Most important is hydration; drinking at least 6-8 glasses of water a day may help prevent stones from forming. Avoiding soda, especially non-clear soda, is often suggested to reduce the formation of uric acid. Depending on the type and cause of the stones, a change in diet is certainly necessary to reduce the risk of them forming again. There are medications to help prevent kidney stones for those patients who suffer from them frequently. Most often these are diuretics, although sodium cellulose phosphate may be prescribed, as it binds calcium in the intestines and keeps it from entering the urinary system.
In cases where a patient suffers from hyperparathyroidism, or the creation of excess parathyroid hormone due to malfunction of the gland or tumor, the parathyroid gland may be surgically removed. Although there are risk factors involved in such a surgery, it is sometimes the only option.
Kidney stones can be painful and even dangerous if left untreated. There are many options for their prevention and treatment.