Kidney Stones

KIDNEY STONES

General Infomation
Definition: 

kidney stones (renal lithiasis) are small, hard deposits that form inside your kidneys. Kidney stones are made of mineral and acid salts. Kidney stones have many causes. In one common scenario, kidney stones form when the urine becomes concentrated, allowing minerals to crystallize and stick together.
Passing kidney stones can be painful. The pain of a kidney stone typically starts in your side or back, just below your ribs, and moves to your lower abdomen and groin. The pain may change as the kidney stone moves through your urinary tract.
Kidney stones usually cause no permanent damage. Apart from pain medication and drinking lots of water, treatment is often unnecessary. However, treatment may help prevent recurrent kidney stones in people with increased risk.

Symptoms: 

A kidney stone may or may not cause signs and symptoms until it has moved into the ureter — the tube connecting the kidney and bladder. At that point, these signs and symptoms may occur:
• Severe pain in the side and back, below the ribs
• Pain that spreads to the lower abdomen and groin
• Pain on urination
• Pink, red or brown urine
• Nausea and vomiting
• Persistent urge to urinate
• Fever and chills if an infection is present
When to see a doctor
Make an appointment with your doctor if you have any signs and symptoms that worry you.
Seek immediate medical attention if you experience:
• Pain so severe that you can't sit still or find a comfortable position
• Pain accompanied by nausea and vomiting
• Pain accompanied by fever and chills

Causes & Complication
Causes: 

Kidney stones often have no definite, single cause. A number of factors, often in combination, create the conditions in which susceptible people develop kidney stones.
Kidney stones form when the components of urine — fluid and various minerals and acids — are out of balance. When this happens, your urine contains more crystal-forming substances, such as calcium, oxalate and uric acid, than the available fluid can dilute. At the same time, your urine may be short of substances that keep crystals from sticking together and becoming stones. This creates an environment in which kidney stones are more likely to form.
Types of kidney stones
Most kidney stones contain crystals of more than one type. Types of kidney stones include:
• Calcium stones. Most kidney stones are calcium stones, usually in the form of calcium oxalate. High oxalate levels can be found in some fruits and vegetables, as well as in nuts and chocolate. Your liver also produces oxalate. Dietary factors, high doses of vitamin D, intestinal bypass surgery and several different metabolic disorders can increase the concentration of calcium or oxalate in urine. Calcium stones may also occur in the form of calcium phosphate.
• Struvite stones. Struvite stones form in response to an infection, such as a urinary tract infection. Struvite stones can grow quickly and become quite large.
• Uric acid stones. Uric acid stones can form in people who are dehydrated, those who eat a high-protein diet and those with gout. Certain genetic factors and disorders of the blood-producing tissues also may predispose you to uric acid stones.
• Cystine stones. These stones represent only a small percentage of kidney stones. They form in people with a hereditary disorder that causes the kidneys to excrete excessive amounts of certain amino acids (cystinuria).
• Other stones. Other, rarer types of kidney stones can occur.
Knowing your type of kidney stone helps to understand what might have caused the stone to form and may give clues as to what you can do to reduce your risk of getting additional kidney stones.

Risk Factors: 

Factors that increase your risk of developing kidney stones include:
• Family or personal history of kidney stones. If someone in your family has kidney stones, you're more likely to develop stones, too. And if you've already had one or more kidney stones, you're at increased risk of developing another.
• Being an adult. Kidney stones are most common in adults age 40 and older, though kidney stones may occur at any age.
• Being a man. Men are more likely to develop kidney stones.
• Dehydration. Not drinking enough water each day can increase your risk of kidney stones. People who live in warm climates and those who sweat a lot may need to drink more water than others.
• Certain diets. Eating a diet that's high-protein, high-sodium and high-sugar may increase your risk of some types of kidney stones.
• Being obese. High body mass index (BMI), increased waist size and weight gain have been linked to an increased risk of kidney stones.
• Digestive diseases and surgery. Gastric bypass surgery, inflammatory bowel disease or chronic diarrhea can cause changes in the digestive process that affect your absorption of calcium and increase the levels of stone-forming substances in your urine.
• Other medical conditions. Diseases and conditions that may increase your risk of kidney stones include renal tubular acidosis, cystinuria, hyperparathyroidism and certain urinary tract infections.

Tests
Tests and Diagnosis: 

If your doctor suspects you have a kidney stone, you may undergo tests and procedures to diagnose your condition, such as:
• Blood tests. Blood tests may reveal excess calcium or uric acid in your blood. Blood tests allow your doctor to check for other medical conditions and to monitor the health of your kidneys.
• Urine tests. Tests of your urine, such as the 24-hour urine collection, may show that you're excreting too many stone-forming minerals or too few stone-inhibiting substances.
• Imaging tests. Imaging tests may show kidney stones in your urinary tract. Imaging tests may include computerized tomography (CT) or, less commonly, X-ray.
• Analysis of passed stones. You may be asked to urinate through a strainer designed to catch any stones you pass. That way, any stones can be collected for laboratory testing. A laboratory analysis will reveal the makeup of your kidney stones. Your doctor uses this information to determine what's causing your kidney stones and to formulate a plan to prevent future kidney stones.

Medication & Prevention
Treatments and Drugs: 

Treatment for kidney stones varies, depending on the type of stone and the cause.
Treatment for small stones with minimal symptoms
Most kidney stones won't require invasive treatment. You may be able to pass a small stone by:
• Drinking water. Drinking as much as 2 to 3 quarts (1.9 to 2.8 liters) a day may help flush out your urinary system.
• Pain relievers. Passing a small stone can cause some discomfort. To relieve mild pain, your doctor may recommend pain relievers such as ibuprofen (Advil, Motrin, others), acetaminophen (Tylenol, others) or naproxen sodium (Aleve).
Treatment for larger stones and those that cause symptoms
Kidney stones that can't be treated with conservative measures — either because they're too large to pass on their own or because they cause bleeding, kidney damage or ongoing urinary tract infections — may require more invasive treatment. Procedures include:
• Using sound waves to break up stones. A procedure called extracorporeal shock wave lithotripsy uses sound waves to create strong vibrations called shock waves that break the stones into tiny pieces that are then passed in your urine. The procedure creates a loud noise and can cause moderate pain, so you may be under sedation or light anesthesia to make you comfortable. The specifics of your procedure may vary depending on the type of equipment your doctor uses.
Extracorporeal shock wave lithotripsy can cause blood in the urine, bruising on the back or abdomen, bleeding around the kidney and other adjacent organs, and discomfort as the stone fragments pass through the urinary tract.
• Surgery to remove very large stones in the kidney. A procedure called percutaneous nephrolithotomy involves surgically removing a kidney stone through a small incision in your back. This surgery may be recommended if extracorporeal shock wave lithotripsy has been unsuccessful or if your stone is very large.
• Using a scope to remove stones. To remove a stone in your ureter or kidney, your doctor may pass a thin lighted tube (ureteroscope) equipped with a camera through your urethra and bladder to your ureter. Your doctor maneuvers the ureteroscope to the stone. Once the stone is located, special tools can snare the stone or break it into pieces that will pass in your urine.
• Parathyroid gland surgery. Some calcium stones are caused by overactive parathyroid glands, which are located on the four corners of your thyroid gland, just below your Adam's apple. When these glands produce too much parathyroid hormone, your body's level of calcium can become too high, resulting in excessive excretion of calcium in your urine. This is sometimes caused by a small benign tumor in one of your four parathyroid glands. A surgeon can remove the tumor or the parathyroid glands.

Alternative Medicine: 

Alternative medicine can't treat kidney stones. But, when combined with your doctor's advice, alternative treatments may help reduce your risk of kidney stones. Some evidence suggests these alternative kidney stone treatments may help:
• Tea. Drinking a cup of black tea or green tea each day could reduce the risk of kidney stones. One study in women found those that drank the most black tea had a slightly lower risk of kidney stones. The study was not rigorous and only involved women, so it doesn't provide strong evidence that drinking tea is helpful for all kidney stones. If you enjoy drinking tea, there may be a chance that continuing to drink tea can help reduce your risk of kidney stones. However, tea contains high oxalate levels. So if your urine has a high oxalate level, your doctor may advise against drinking tea.
• Lemon juice and orange juice. Theoretically, drinking lemon juice or orange juice could reduce the risk of kidney stones. The citric acid levels in lemon juice and orange juice could reduce calcium levels in your urine, leading to fewer calcium kidney stones. But no studies have proven this theory. If you enjoy drinking water flavored with lemon or drinking orange juice, you might find that this helps reduce your risk of kidney stones. But there is not enough evidence to suggest everyone should try this.

Prevention: 

Lifestyle changes
You may reduce your risk of kidney stones if you:
• Drink water throughout the day. Drink more water throughout the day. For people with a history of kidney stones, doctors usually recommend passing about 2.6 quarts (2.5 liters) of urine a day. Your doctor may ask that you measure your urine output to ensure that you're drinking enough water. People who live in hot, dry climates and those who exercise frequently may need to drink even more water to produce enough urine.
• Eat fewer oxalate-rich foods. If you tend to form calcium oxalate stones, your doctor may recommend restricting foods rich in oxalates. These include rhubarb, beets, okra, spinach, Swiss chard, sweet potatoes, 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 nuts and legumes. This may help reduce your chance of developing kidney stones.
• Continue eating calcium-rich foods, but use caution with calcium supplements. The calcium in the food you eat doesn't 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, though, as these have been linked to an increased risk of kidney stones. You may reduce the risk by taking supplements with meals.
Ask your doctor for a referral to a dietitian who can help you plan meals that will help reduce your risk of kidney stones.
Medications
Medications can control the level of acidity or alkalinity 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:
• Calcium stones. To help prevent calcium stones from forming, your doctor may prescribe a thiazide diuretic or a phosphate-containing preparation.
• Uric acid stones. Your doctor may prescribe allopurinol (Zyloprim, Aloprim) to reduce uric acid levels in your blood and urine and a medicine to keep your urine alkaline. In some cases, allopurinol and an alkalinizing agent may dissolve the uric acid stones.
• Struvite stones. To prevent struvite stones, your doctor may recommend strategies to keep your urine free of bacteria that cause infection. Long-term use of antibiotics in small doses may be useful to achieve this goal.
• Cystine stones. Cystine stones can be difficult to treat. Your doctor may prescribe certain medications to alkalinize the urine or to bind the cystine in the urine in addition to recommending an extremely high urine output.

By Anonymous on 02 May 2011