An illustration demonstrates what a kidney stone looks like.
If a kidney stone coincides with chills and a fever of 100 degrees or more, seek immediate medical care. (For Spectrum Health Beat)

Ask anyone who has suffered from a kidney stone and they just might call it the most painful experience of their life.

Unfortunately, this common condition afflicts about 1 in 12 Americans, according to Hector Pimentel, MD, a urologist with Spectrum Health.

8 facts to know about kidney stones:

1. It takes months to years for a stone to form.

Kidney stones form slowly in the kidney and they can stay there without causing any pain or problems, Dr. Pimentel said.

“You can have stones for years and not know it,” he said. “If it’s not causing any blockage or hurting the kidney, we can just keep an eye on them. But once they make their way out of the kidney, they are typically incredibly painful.”

When they leave the kidney, they squeeze through the ureter, into the bladder and then eventually out through the urethra.

2. Kidney stone pain is different from muscular back pain.

Dr. Pimentel said people sometimes mistake other pains for kidney stone pain. Kidney stone pain is very sharp, typically one-sided and is located in the flank—or the area on each side of your spine between the bottom of your rib cage and your hips.

“Usually it will not get better with any activity,” he said. “If a change in your position makes it feel better, then that’s a pretty good sign that it’s muscular pain and not kidney stone pain.”

It will, however, come and go as the stone passes through the urinary tract.

Other symptoms may accompany the pain, including fever and chills, nausea and vomiting, cloudy urine, urgent need to urinate, blood in your urine and/or burning when you urinate.

3. If you have a kidney stone and you develop a fever and chills, go to the emergency department.

The pain and other symptoms caused from passing a kidney stone are typically not dangerous or life-threatening as long as you’re able to stay well-hydrated, Dr. Pimentel said.

“The thing that’s really dangerous is fever of 100 degrees or more and chills,” he said. “If you have a kidney stone blocking your kidney, you can get sepsis very quickly and it will not get better until we fix it.”

That’s why he recommends seeking medical treatment right away if you develop those symptoms.

4. Not every kidney stone is created equal.

Kidney stones range from very small (a few millimeters) to very large (8 centimeters), Dr. Pimentel said. There are also different types of kidney stones—calcium, which is the most common type, and then struvite, uric acid and cystine.

Depending on the size of your stone, you may or may not be able to pass it on your own, without surgical intervention.

“A stone that’s 10 millimeters or larger almost never will pass on its own,” Dr. Pimentel said. “Most people will need some kind of treatment.”

Stones can get so large that they block almost the entire kidney. Those stones, commonly called staghorns, stay in the kidney and cause blood in the urine and infections.

5. There’s medical help if you can’t pass the stone on your own.

There are three surgical options available, depending on each person’s situation, Dr. Pimentel said.

The least invasive and most commonly used is shock wave lithotripsy.

“It looks like you’re getting an ultrasound,” Dr. Pimentel said. “The waves go through the body and because our bodies are made up of water, it does not hurt us. When it hits the stone, it’s like the wave hitting the shore of the ocean. It breaks up the stone, hopefully to dust so you can pass it on your own without pain.”

A second option, called ureteroscopy, involves the doctor passing a thin, flexible scope through your bladder and ureter into the kidney, then using a laser to break up the stone and a small basket to trap and pull out the fragments.

For large stones more than 1 inch in diameter, a more invasive surgery is required, Dr. Pimentel said. This involves using a special instrument to enter the kidney through a 1/2-inch incision in the back.

“It breaks the stone into dust and allows it to be sucked out at the same time,” he said.

Doctors use this method with stones that would require multiple sessions of the lower risk surgery to remove.

6. Overdoing calcium or vitamin C supplements can contribute to kidney stone formation.

Dr. Pimentel urged people to talk with their primary care doctor to be sure they’re getting the right amount of calcium, but not too much.

“Speak to your doctor before taking supplements and don’t just do it on your own,” he said. “We want to make sure you’re not increasing your risk of kidney stones, without any benefit.”

7. If you have one kidney stone, you just might have another.

If you have had one kidney stone, you are at increased risk of having another, Dr. Pimentel said. Those who have developed one stone have about a 50% risk for developing another within five to seven years.

One thing that can help lower that risk: Save your stone when you pass it so the doctor can analyze it to see what kind of stone it is and recommend treatment based on the results.

Another test that can help is a 24-urine collection analysis, which can show what’s making you at higher risk for stone formation.

“The 24-hour urine testing can really drill down on exactly what you need to change in your diet,” he said.

8. Hydration is the best prevention.

People who are prone to forming stones should be drinking 90 ounces of fluid a day—preferably water, Dr. Pimentel said.

He advises his patients to get a 20-ounce water bottle and to fill and drink four per day, as a rough guide.

A healthy diet also helps.

“The best thing for people who have kidney stones to remember is that a nice, general healthy diet that avoids packaged foods and heavy meat intakes help, because salt is typically a big risk factor for stones,” he said.