What causes kidney stones?
Medical research has not been able to pinpoint an exact single cause of kidney stones as various combined factors play a role in the development of these crystallised formations. As such, when in place, these factors increase a person’s risk.
In those with kidney stones, crystal-forming substances, such as oxalate (salts of oxalic acid), calcium and uric acid (among others) are found in greater abundance (higher quantity) than fluid (water) in the urinary system. A lack of urine (less than 1 litre per day) being produced in the system means that the body becomes unable to dilute these substances. The amount of urine that is present lacks the components and substances needed to counteract the clumping together of crystals which form. Minerals and salts are thus unable to be watered down, and instead form hardened deposits.
Causal influences and risk factors can also include:
- Imbalances in diet (nutrition): Inadequate fluid intake, high amounts of animal proteins, high sodium (salt) intake, as well as excessive sugar consumption, vitamin A, C and D supplementation and high-oxalate foods such as spinach can contribute to kidney stone development. Low levels of dietary calcium intake can also interfere with the calcium / oxalate balance, causing increased excretion of oxalate, which can lead to the formation of kidney stones.
- Dehydration: Strenuous exercise and or / a lack of fluid intake to replenish the body can lead to dehydration. This can increase a person’s risk for the development of kidney stones. Dehydration can also occur due to illness (such as diarrhoea), obstructions to the natural flow of urine in the urinary tract, and climatic conditions (very hot and dry weather).
- A family history of kidney stones: It has been established that heredity (certain genes) do play a role in making some individuals more susceptible to the development of kidney stones. One reason for this is that high levels of calcium in urine can be passed through family generations. Some hereditary disorders, although rare, such as metabolic conditions or kidney problems like renal tubular acidosis, have also been found to predispose families to the formation of kidney stones.
- Certain medications, procedure risks and or / related medical conditions: Urinary tract infections, metabolic abnormalities and inherited disorders, such as hyperoxaluria or cystinuria (which alter the composition or urine), gout (high quantities of uric acid), hypercalciuria (high levels of calcium content in urine), hyperoxaluria (excessive levels of oxalate in urine), hyperparathyroidism (over-secretion of the parathyroid hormone due to overactive parathyroid glands), renal tubular acidosis (accumulation of acid in the body when the kidney do not acidify the urine), hypertension (high blood pressure), diabetes, obesity, cystic fibrosis (an inherited condition that damages the lungs and digestive system) and inflammatory bowel disease. Those who have undergone ostomy surgery (or bowel diversion surgery) or an intestinal bypass may also be at increased risk for the formation of kidney stones. Medications which also carry some degree of risk for kidney stones include some diuretics, antacids containing calcium, some antibiotics and a drug used to treat HIV (protease inhibitor indinavir – Crixivan / indinavir), this is because they take longer to be excreted through the kidneys.
What are some other risk factors that may cause kidney stones?
- Those who have had at least one kidney stone in their lifetime are typically prone to others down the line.
- Pregnancy-related changes can sometimes (although not commonly) result in the formation of kidney stones. One reason may be due to an increase in progesterone (hormone) levels slowing down the passage of urine, which when combined with a reduced fluid intake as a result of decreased bladder capacity (as the uterus grows larger), may lead to the formation of kidney stones. Research has not been able to determine a clear cause of kidney stones during pregnancy, but the aforementioned facts may have an influence on women who have a predisposition to the condition, or who experience an increase in urinary calcium excretion.
Can diabetes increase risk for kidney stones?
Insulin, a peptide hormone which is produced by beta cells in pancreatic islets is central to diabetes as a condition. The body is either not naturally producing enough of it or is unable to use the substance sufficiently (i.e. in the regulation of blood sugar levels). It is thus important to carefully treat diabetes medically as the effects can result in a variety of health problems throughout the body, including the kidneys.
As such, there is a link between diabetes and risk of developing kidney stones. A person with type 2 diabetes (insulin resistance / deficiency – wherein the body is unable to effectively use insulin produced in the pancreas) can experience very acidic urine. In this way, the risk for kidney stones increases.
If being treated for diabetes, it is wise to keep kidney stone risk factors in mind and work closely with a treating doctor to ensure that the chances of developing these painful deposits are kept low.