Kidney stones – also known as renal calculus, renal lithiasis or nephrolithiasis – can affect individuals at some time in their lives, but usually after the age of 40. Fortunately, many individuals can pass these stones without any permanent damage, but in many cases their passing can be extremely painful and is a common cause for individuals going to the hospital.
What are kidney stones?
As the kidneys filter waste from the blood, they create urine. Sometimes salts and other minerals in urine stick together to form small kidney stones. These stones can range from the size of a sugar crystal to a tennis ball, but they are rarely noticed unless they cause a blockage. They may cause intense pain if they break loose and push into the ureters, the narrow ducts leading to the bladder. Kidney stones have many causes and can affect any part of your urinary tract — from your kidneys to your bladder. Often, stones form when the urine becomes concentrated, allowing minerals to crystallize and stick together.
What causes kidney stones?
In many cases kidney stones often have no definite, single cause, although several factors may increase your risk of getting a stone. Drinking too little water is the most common cause of kidney stones.
Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute. At the same time, your urine may lack substances that prevent crystals from sticking together, creating an ideal environment for kidney stones to form.
What are some risk factors for getting kidney stones?
Factors that increase your risk of developing kidney stones include the following:
• Family or personal history. If someone in your family has kidney stones, you are more likely to develop stones. If you have already had one or more kidney stones, you are at increased risk of developing another.
• Dehydration. Not drinking enough water each day can increase your risk of kidney stones.
• Certain diets. Eating a diet that is high in protein, sodium and sugar may increase your risk of some types of kidney stones. This is especially true with a high-sodium diet. Many of us here in Anguilla consume too much salt.
• Obesity. High body mass index (BMI), large waist size and weight gain have been linked to an increased risk of kidney stones.
• Other medical conditions. Diseases and conditions that may increase your risk of kidney stones include renal tubular acidosis, cystinuria, hyperparathyroidism, certain medications and some urinary tract infections.
What are some symptoms of kidney stones?
When kidney stones move through the urinary tract, they may cause:
• Severe pain in the back, abdomen (belly), or groin
• Frequent or painful urination
• Blood in the urine
• Nausea and vomiting
Small stones may pass without causing symptoms. Pain caused by a kidney stone may change — for instance, shifting to a different location or increasing in intensity — as the stone moves through your urinary tract.
Diagnosis
If you have sudden, severe pain in the back or belly, it is best to seek medical care right away. Abdominal pain is associated with many other conditions, including emergencies like appendicitis and ectopic pregnancy. Painful urination is also a common symptom of a urinary tract infection or a sexually transmitted infection.
Kidney stones are rarely diagnosed before they begin causing pain. This pain is often severe enough to send patients to the emergency room, where a variety of tests can uncover the stones. These may include a CT scan, X-rays, ultrasound, and urinalysis. Blood tests can help look for high levels of minerals involved in forming kidney stones.
Treatment
Treatment for kidney stones varies, depending on the type of stone and the cause.
If a kidney stone seems small enough, your doctor may recommend you take pain medicine and wait for the stone to pass out of the body on its own. During this time, your doctor may recommend that you drink enough water and fluids to keep urine clear — about eight to 10 glasses a day.
There are prescription medications that can help the body pass a kidney stone.
If a stone is too large to pass on its own, several treatment options are available.
The most common medical procedure for treating kidney stones is known as extracorporeal shock wave lithotripsy (ESWL). This therapy uses high-energy shock waves to break a kidney stone into little pieces. The small pieces can then move through the urinary tract more easily.
A surgeon might also use surgery to remove kidney stones.
Kidney stone analysis
Once a kidney stone has passed or been removed, your doctor may want to know what it is made of. Nearly 80% of kidney stones are calcium-based. The remainder are made primarily of uric acid, struvite, or cystine. A chemical analysis can determine which type of stone you have. Once you know, you can take steps to prevent new ones from forming in the future.
Prevention
Prevention of kidney stones may include a combination of lifestyle changes and medications.
Lifestyle changes include drinking lots of fluid especially if you live in hot islands like Anguilla. If your urine is light and clear, you are likely drinking enough water.
Eat fewer oxalate-rich foods. If you tend to form calcium oxalate stones, your doctor may recommend restricting foods rich in oxalates. These include beets, okra, spinach, Swiss chard, nuts, tea, chocolate and soy products.
Choose a diet low in salt and animal protein. Reduce the amount of salt you eat and choose nonanimal protein sources such as legumes.
Continue eating calcium-rich foods, but use caution with calcium supplements. Calcium in food does not have an effect on your risk of kidney stones. Continue eating calcium-rich foods unless your doctor advises otherwise. Ask your doctor before taking calcium supplements as these have been linked to increased risk of kidney stones. You may reduce the risk by taking supplements with meals. Diets low in calcium can increase kidney stone formation in some people.
Medications can control the amount of minerals and acid in your urine and may be helpful in people who form certain kinds of stones. The type of medication your doctor prescribes will depend on the kind of kidney stones you have.
Conclusion
Most individuals associate kidney stones with severe pain. In some cases individuals can have kidney stones and pass them with little or no symptoms. If stones grow to sufficient size (usually at least 3 millimeters (0.12 in)) they can cause blockage of the ureter. This leads to pain most commonly beginning in the flank or lower back and often radiating to the groin. This pain is often known as renal colic and typically comes in waves lasting 20 to 60 minutes. Various treatment options are available for kidney stones and once treated individuals are encouraged to take steps to prevent recurrences.
Ask Your Doctor is a health education column and is not a substitute for medical advice from your physician. The reader should consult his or her physician for specific information concerning specific medical conditions. While all reasonable efforts have been made to ensure that all information presented is accurate, as research and development in the medical field are ongoing, it is possible that new findings may supersede some data presented.
Dr Brett Hodge is an Obstetrician/Gynaecologist and Family Doctor who has over thirty two years in clinical practice. Dr Hodge has a medical practice in The Johnson Building in The Valley (Tel: 264 4975828).
