Kidney stones usually refer to crystalized “stones” that form from the urine, usually starting in the kidney. Actually these stones can be found anywhere that urine passes, including the kidneys, ureters (thin tubes that connect the kidneys to the bladder), and bladder. Urinary stones form from a variety of substances including calcium combined with oxalate or phosphorus, uric acid, and even from compounds formed from certain urinary tract infections. This stones form in special environments within the urine, most commonly during times of dehydration, but they may also form when there is blockage to the flow of urine or during infections. This section will discuss how stones are identified, treated, and prevented.
Most people find out they have a kidney stone when they get severe pain anywhere from their back radiating all the way to the groin. The pain occurs when stones block the drainage of urine and cause back pressure. There may also be blood in the urine or symptoms of a urinary tract infections. Many people also have nausea and vomiting associated with passing stones. The severity of these symptoms usually leads people to the Emergency Room where they are evaluated with a CT scan, urine analysis, and basic blood tests. Some people have stones without their knowledge because those stones do not cause blockage. These are sometimes found on imaging done for another symptoms or, in rare cases, after stones have grown so large they cause permanent damage to the kidneys or bladder. In most cases, a CT scan is the best method for finding urinary stones when any of the above symptoms are present.
Treatment of kidney stones depends on the size of the stone and the severity of the symptoms. Some stones that are small are able to be passed without surgical intervention. Occasionally medicines are used to help facilitate the passage. A few types of rare stones are able to be dissolved with medications. For those that do not or will not pass spontaneously, there are three different procedures to treat stones in the kidneys and ureters. The first is called Extracorporeal Shockwave Lithotripsy, or ESWL, and is performed with a machine that pushes against the body and sends shockwaves of energy to break of the stones. There are no incisions or instruments passed into the body. Another method used is call ureteroscopy, which is performed by passing a small camera into the bladder through the urinary channel and up to the level of the stone. A small laser fiber and basket can then be used to fragment and remove the stone. The third method is called percutaneous nephrolithotomy and is performed by making a small incision in the back and opening a small tube directly into the kidney. This is reserved for large stones. All of these procedures may also require the placement of a stent or rubber tube that courses from the kidney to the bladder. This allows urine to pass around the stone and allows for healing after stones are removed. These types of stents are temporary only. Stones in the bladder are usually removed through a camera entering the urine channel or through a small incision directly into the bladder.
Stones that form in the urinary system are often preventable. Dehydration caused from not drinking enough water is the most preventable cause of stones as this allows the urine to be more concentrated and stones to appear. By simply drinking enough water, most people can avoid kidney stones regardless of their diet. There are certain foods which can lead to stones. There are also anatomical issues that make urination or urinary drainage slower and can lead to stone formation. Your urologist will not only help treat your stone, but will also help you identify the cause and develop a strategy to prevent further stones from forming.