Everything you need to know about kidney stones

It seems amazing that something so tiny can cause so much suffering. But while a small minority of people are genetically destined to develop a kidney stone, you may greatly reduce your odds of getting one with some simple lifestyle changes.

• Usually, your kidneys efficiently flush microscopic particles of salts and minerals into the ureter and then they're expelled when you urinate. Trouble looms when chemical imbalances and other processes cause these tiny particles to bind together into crystals, which over time grow into a kidney stone.
• When the stone moves from the kidney into the delicate ureter, it produces anything from a nagging ache to excruciating pain, often accompanied by nausea and vomiting. This blockage may trigger a urinary tract infection.
• Sometimes stones get stuck in the kidney, initiating an infection but typically not causing immediate pain.

Doctors don't entirely understand all the physiological changes that lead to kidney stones.

• Suspected causes of kidney stones include high levels of urinary calcium and oxalate (a chemical that enables stone formation); excessive absorption of calcium from the intestine; too much dietary sodium; chemical imbalances; diseases (such as gout, recurrent urinary tract infections and hyperparathyroidism); and even some medications.
• Kidney stones are categorized by their chemical composition. It’s a good bet that yours is made of calcium and oxalate, a combination responsible for 70 percent to 80 percent of all stones.
• About seven percent are formed from uric acid; and a small fraction are either struvite stones (almost always caused by urinary tract infections) or cystine stones, which result from a rare genetic disorder.

• Watchful waiting to see if a kidney stone will pass on its own.
• High volumes of water to help flush the stone out of the urinary tract.
• Narcotic analgesics and anti-inflammatory medications to control pain.
• Antibiotics if a urinary tract infection occurs.
• Non-surgical or surgical procedures, if needed, to eliminate a stone.

• Treat a urinary tract infection promptly. Struvite stones form only in infected urine. If you have an infection, call your doctor.
• Rehydrate after sweating. If you live in a warm climate or you participate in strenuous physical activities, drink more than the recommended three to four litres (three to four quarts) of liquids a day — enough to keep your urine almost colourless. Carry a water bottle with you as a reminder.
• Maintain a healthy weight. Kidney stones seem to be more common among overweight people. But if you need to lose weight, don't go on a crash diet; this can make you produce more uric acid that promotes kidney stones. Lose weight gradually.

Although this may not be much consolation, you're not alone. One in 10 Canadians will develop kidney stones at some point in their lives.

• For excellent overviews of kidney stone symptoms, treatments and recommended lifestyle changes, contact one of the provincial chapters of the Canadian ­Kidney Foundation, or visit its website online at www.kidney.ca.

Kidney stones can hurt — a lot. In fact, the condition is commonly cited as one of the most painful in all of medicine. Even stones smaller than a pencil eraser can cause misery and a trip to the emergency room. Keep this guide in mind and reduce your risk with healthy lifestyle changes and be sure to visit your doctor if you're experiencing any pain.