Kidney stones are the formation of crystalline structures in the urinary tract (which includes the kidneys, ureters, and bladder). These stones can cause pain, infection, and kidney damage. Stones can be small, from 1 mm to very large, filling up an entire kidney.
For patients experiencing their first stone episode, the pain can be so severe and sudden that it stops them in their tracks. Without prior knowledge of what a stone episode feels like, it can be confusing and frightening to go through this amount of discomfort, which is usually described as the worst pain someone has ever experienced. A trip to the emergency room is usually required to make the diagnosis and provide treatment for an active kidney stone. X-rays, usually a CT scan, can be used to confirm that a stone is present.
Stone pain is often described as stabbing and extremely severe. Women commonly say that it is worse than having a child. The pain can start in the upper back (flank) and then migrate to the abdomen and groin. Changing positions does not help relieve the pain. The pain of a kidney stone is primarily due to blockage of the urine drainage coming down the small tube called the “ureter” that connects a kidney to the bladder. anatomy-overview1 It is thought that the increased pressure stretches the kidney and ureter, causing the pain. This is why stone pain can come and go in waves, as the drainage tube is periodically blocked by the stone trying to make its way out. As the stone moves further down the tube, the pain experienced moves down the body. Other symptoms common during a stone episode include seeing blood in the urine, nausea & vomiting, and feeling the urge to urinate. Once a stone is passed and makes it way out of the ureter tube and into the bladder, most patients describe a sensation of instant relief as the blockage and pressure is relieved. However, stones can take from days to weeks to pass. .
Most doctors feel that kidney stones only cause pain if they are blocking the ureter and trying to pass down towards the bladder. Stones that are not obstructing, such as those located in the kidney’s calyxes, are generally thought to be non-painful. This explains why some patients can have extremely large stones filling up their entire kidney with no or minimal pain. However, it does appear that some non-obstructing stones can cause pain because of either blockage of small tubular structures in the kidney itself (the collecting tubules) or for other unclear reasons. Supporting this view is a recent medical journal article suggesting that the treatment of small non-obstructing “papillary” stones may provide pain relief. (Gyor et al, multi-institutional assessment of ureteroscopy laser papillotomy for chronic pain associated with papillary calcifications, J Ural 2011) Additionally, testimonials from many kidney stone patients (including a urologist with a personal history of kidney stones) suggest that some non-obstructing stones can cause pain. .
Kidney stones affect 1 out of 10 people during their lifetimes. They are more common than most people realize. There are many factors that determine whether someone will develop a stone with some being under a person’s control while others are out of their hands. Common factors influencing kidney stone development: 1. Gender: Men are two to three times more likely to form stones 2. Race: Caucasians have the highest stone rates as compared to other races 3. Age: Stones occur most commonly between the 20s to 50s 4. Geography: Those living in hot dry environments are at increased risk. Additionally, those living in the Southeastern United States appear to be at particularly increased risk of forming stones. 5. Seasonal climate: Stone development is more common during the summer months due to dehydration from higher summertime temperatures and possibly also from higher concentrations of calcium in urine resulting from increased sun exposure which can lead to higher levels of Vit D production. 6. Occupation: Those working in jobs with exposure to climate and dehydration are more prone to stone development. 7. Body weight: There are higher rates of stones in those with increased weight and body mass index. 8.Genetics and medical conditions: Individuals with a history of some conditions, such as medullary sponge kidney or renal tubular acidosis are prone to forming stones. Those with a personal family history of stones may have a two to three times increased risk of forming stones. 9. Infections: Chronic urinary tract infections can lead to the development of infection-related stones, known as struvite stones.
There are many factors lead to the development of kidney stones. Kidney stones are formed from substances known as soluble salts. Calcium oxalate-the most common type of kidney stone is a soluble salt. It can exist in a dissolved form or in a solid, crystalline form. When the concentration of soluble salt in solution is high enough, it will begin forming into solid crystals, in a process known as precipitation. An example of common soluble salt is sodium chloride in seawater. When seawater is allowed to stand and evaporate, the previously dissolved sodium chloride precipitates out of solution in the form of sea salt. Urine contains many chemical elements that can also combine to form soluble salts. These chemicals normally remain in a dissolved form in the urine. Surprisingly, the concentrations of these salts in urine are usually much higher than what could remain dissolved in pure water. This unusual situation can occur because of the presence of inhibitors in urine that make it more difficult for soluble salt crystals to develop. Some kidney stone inhibitors are substances from our diet, such as citrate, while others inhibitors are proteins manufactured by our bodies to help prevent the development of stones. Two examples of inhibitor proteins made by our bodies include Tamm-Horsfall protein and nephrocarcinoma. Kidney stones initially form in a process known as nucleation when the factors encouraging salt crystals to develop outweigh the factors inhibiting salt crystals to develop. These crystals will continue to get larger over time and result in a detectable kidney stone if the conditions in urine remain favorable for stone formation. Other important factors that affect the development of kidney stones include the amount of urine a person makes, with lower volumes leading to more concentrated urine, and the presence of slowe drainage, which can make it easier for crystals to gather and combine. The presence of a binding site can also make it easier for stones to start forming by acting as an “anchor” for crystals to develop on. A natural binding site is thought to be the small calcifications that can develop in kidney tissue known as “Randall’s plaques”. A visual timeline of kidney stone formation.
Yes!, there are many effective ways to help prevent another stone. Basic dietary changes can reduce your chances of forming another stone by half while more involved medical treatment can reduce that even further. While these changes may not guarantee that you will not form another stone, they can make it less likely that you will have to experience another painful stone episode .
If you think you are passing a stone, signs indicating that you should seek immediate medical attention include:
1. Fever above 101.5 degrees Fahrenheit,
2. Other symptoms of a urinary tract infection with a stone, including burning during urination, cloudy urine, or bad-smelling urine,
3. Persistent nausea and vomiting,
4. Intolerable pain,
5. Certain medical conditions can make passing a stone potentially more dangerous, including those with only one kidney, those with diabetes, or those with decreased kidney function.
It appears that stones can form in as short a period of time as three months. This is based on research of soldiers deploying to Kuwait and Iraq where the mean time to development of a symptomatic stone was 93 days in the hot desert environment.
