Does It Hurt When a Kidney Stone Passes?

There's no way around it: yes, it usually hurts when a kidney stone passes. To minimize pain and prevent future stones from forming, it's helpful to understand what a kidney stone is and how it can be treated.

What Is A Kidney Stone?

• A kidney stone is a solid aggregation of crystals that come from dissolved minerals in the urine. Usually, these crystals don't form, because chemicals in urine keep them in a liquid state, but, for a variety of reasons, sometimes these chemicals don't work properly.

Why Does It Hurt?

• Kidney stones can be minuscule, in which case they can move through the kidneys, ureter, bladder and urethra without causing any pain. On the other end of the scale, kidney stones can reach the size of a golf ball.

  When they are around 2-3 mm in diameter or larger, they stretch the walls of the ureter and the renal pelvis (the opening from the kidney to the ureter). These muscles respond by spasming in an attempt to push the kidney stone out. This stretching and spasming is what causes the sometimes excruciating pain associated with a kidney stone. Once the stone is through the ureter, the pain usually ceases, and shortly afterward, the kidney stone will be passed, probably during urination. If the stone is larger than about 6mm, however, it may need medical intervention in order to pass. About one in ten kidney stones needs a doctor's help to pass.

Types

• There are several different types of kidney stones. The most common are formed from calcium oxalate. Calcium phosphate stones also occur quite often. These stones come from everyday nutrients we take in. People with urinary tract infections may get struvite, or infection, stones, which result from the action of bacteria in their urine. People with metabolic disorders may also get kidney stones, as may children on a special high-fat diet to prevent epileptic seizures. Depending on their makeup, kidney stones look very different from one another, which can help the layman to figure out what his kidney stone is made of.

Treatment

• If you suspect you have a kidney stone, you should see a doctor as soon as you can. If you're in a lot of pain, visit Urgent Care or the emergency room. When you do, you'll probably receive a CAT scan or an ultrasound to determine whether you do indeed have kidney stones, and what their estimated size is. The doctor will usually take blood and urine samples, to gauge your kidney function. You may also receive IV or oral pain medication.

  Unless a kidney stone is especially large (usually more than about 6mm), doctors usually recommend you let it pass on its own - in other words, let it come out with your flow of urine. If it's too large to pass this way, there are several options for removing it. The most common way is by using shock waves to break it into smaller pieces, which then come out in your urine. A doctor can also remove the stone surgically, either by keyhole surgery or conventional means. It depends on where the stone is: if it's in the kidney, an incision may have to be made in your side in order to remove it. A stent can also be put into the ureter, which will hold it open so that stones can pass through without it spasming or stretching.

  If your doctor has recommended you let your stone pass on its own, you can take ibuprofen to help with pain. (Ask your doctor how much you should take and how frequently you should be taking it.) Warm baths can help relieve pain too, as can heating pads. Make sure you also drink lots of water. Your doctor might ask you to urinate into a small strainer to catch the kidney stone when it passes. He will collect the stone and analyze it: depending on its type, he can then suggest dietary changes or other treatment.

Time Frame

• If a stone is small enough to pass on its own, doctors usually give it around four weeks to pass before they intervene. If a stone doesn't look like it will pass by itself, doctors will perform procedures to remove it as soon as possible.

Prevention/Solution

• To minimize the risk of forming kidney stones, doctors recommend drinking at least three quarts of water a day. Depending on the type of kidney stone you have, the treatment will be different. You may be prescribed a special diuretic, which will help prevent future stones from forming. You may also be placed on a low-protein, low-sodium diet, or told to eat limited amounts of foods containing oxalic acid, such as sweet potatoes.