Kidney stones are one of the most common problems associated with kidneys. Millions of people have had either one or more kidney stone episodes. They cause excruciating pain. Sometimes they pass from your kidneys out of your urinary tract on their own, but sometimes it requires in-depth treatment to get rid of them.

Definition

Kidney stones are small, hard rocks (crystals) that are formed within the kidneys when chemicals in the urine become concentrated to the point that they form solid crystals. The shape of a stone may be round, jagged or branch-like and the texture of the stone may be rough or smooth. The size of the stone may vary from as large as a speck of sand to pebbles to stones as large as golf balls.

Causes

More than 90% of individuals with kidney stones have a chemical abnormality in their blood or urine that contributes to the tendency to form the stones. Not drinking enough water or other fluids may also contribute to forming stones as an inadequate intake of fluids causes the kidneys to produce less urine, or urine that is highly concentrated. The smaller the daily volume of urine, the more likely it is that a person’s kidneys would form stones. When kidney stones are large or there is more than one, they may block the flow of urine.

Prevention

Research has shown that a variety of diet-related factors may contribute to the formation of kidney stones, but the good news is that certain foods and beverages can also help prevent new stones from forming.

    • Liquids. Drinking enough liquids each day helps to keep your urine diluted, which greatly reduces your chances of forming kidney stones. Drink 10 to 12 glasses of liquids each day. At least half of the liquid you drink should be water. The other liquids could be any beverages you like (juice, milk, coffee, or flavoured beverages). Drink alcohol only in moderation or not at all. It is important to drink at least one cup of liquid at bedtime.
    • Sodium (salt). Reduce, or keep to a minimum, the amount of salt that you eat: Avoid using salt at the table; reduce or omit salt in cooking; reduce or omit high-sodium foods; and choose unsalted pretzels, crackers and popcorn instead of salty snacks.

Treatment

There are several factors that influence the ability to pass a stone. These include the size of the person, prior stone passage, prostate enlargement, pregnancy and the size of the stone. A 4 mm stone has an 80% chance of passage while a 5 mm stone has a 20% chance. Stones larger than 9 to 10 mm rarely pass without specific treatment.

With ample fluid intake, most kidney stones eventually pass through the urinary tract on their own within 48 hours. Pain medications are used for symptom relief. When over-the-counter medications are insufficient for pain control, soothing medicines may be prescribed. Intravenous pain medications can be given when nausea and vomiting are present.

Medications, such as calcium channel blockers and alpha-blockers may be prescribed for people who have stones that do not pass through the urinary tract rapidly.

If the kidney stones do not pass on their own, a procedure called lithotripsy is often used where shock waves are used to break up a large stone into smaller pieces that can then pass through the urinary system.

When should you see a doctor?

You should call a doctor if you have any of the following signs:

    • Extreme pain in your back or side that will not go away
    • Blood in your urine
    • Fever and chills
    • Vomiting
    • Urine that smells bad or looks cloudy
    • A burning feeling when you urinate.

These may be signs of a kidney stone that needs a doctor’s care.

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