Kidney stones are hard pebble-like objects that can form inside your kidneys. They’re made of minerals and salts. You might hear your doctor call them renal calculi, nephrolithiasis, or urolithiasis.
Kidney stones are small usually between the size of a kernel of corn and a grain of salt. They can form when your body has too much of certain minerals, and at the same time doesn’t have enough liquid. The stones can be brown or yellow, and smooth or rough.
- Intense pain in your side or back, below the ribs (your doctor might refer to it as renal colic)
- Pain in your groin and lower abdomen
- Pain that comes and goes and ranges in severity
- Pain when you pee
- Going to the bathroom more often than you usually do
- Pee that’s cloudy, pink, red, or brown, or smells bad
- Feeling like you need to pee all the time
- Fever and chills if you have an infection
- Nausea and vomiting
- Burning sensation when you pee
- Less urine when you do pee
Different things can bring on kidney stones, including what you eat and certain medications. If you or someone in your family has had a kidney stone, you’re more likely to have them.
Kidney stones happen when your pee has a high concentration of minerals and other substances like calcium, oxalate, and uric acid that come together to make crystals. Crystals stick together to make one or more stones. Stones happen when your urine doesn’t have enough fluid and other substances to keep them from happening.
- Other medical conditions that cause nephrolithiasis
Many diseases can play a role in one or more types of kidney stones to form.
- Certain genetic diseases
One example is medullary sponge kidney, a birth defect that causes cysts to form in the kidneys.
- Type 2 diabetes
It can make your urine more acidic, which encourages stones.
This condition makes uric acid build up in the blood and form crystals in the joints and the kidneys. The kidney stones can become large and very painful.
Your parathyroid glands can pump out too much hormones, which raises calcium levels in your blood and urine.
- Renal tubular acidosis
This kidney problem causes too much acid to build up in the body.
- Medications that cause nephrolithiasis
- Certain antibiotics, including ciprofloxacin and sulfa antibiotics
- Some drugs to treat HIV and AIDS
- Certain diuretics used to treat high blood pressure. But some thiazide-type diuretics actually help prevent stones.
The best way to prevent most kidney stones is to drink enough fluids every day. Most people should drink eight to 12 cups of fluid per day. If you have kidney disease and need to limit fluids, ask your doctor how much fluid you should have each day. Limiting sodium and animal protein (meat, eggs) in your diet may also help to prevent kidney stones.
Never start or stop any treatment or diet without talking to your doctor first.
Types of kidney stones
The different types of stones are made of different types of substances. It’s important to know the type of stone you have, so you can know what may have caused it and how to prevent it.
If you pass a kidney stone, you should take it to your doctor so they can send it to the lab and find out what kind it is:
- Calcium stones
Most kidney stones are made from calcium, in the form of calcium oxalate. There are two kinds of calcium stones:
- Calcium oxalate
Oxalate is a substance made daily by your liver. Some fruits and vegetables, as well as nuts and chocolate, are high in it. Your body absorbs the substance when you eat these foods. Other things that can make the concentration of calcium or oxalate in your urine to rise are taking high doses of vitamin D, intestinal bypass surgery and certain metabolic disorders.
- Calcium phosphate
This type of stone happens more often in people with metabolic conditions, like renal tubular acidosis or with people who take medications to treat migraines or seizures.
- Struvite stones
These can form from a urinary tract infection (UTI). The bacteria that cause the infection make ammonia build up in your urine. This leads to formation of the stones. The stones can get large very quickly.
- Uric acid stones
These form in people who lose too much fluid because of chronic diarrhea; eating a high-protein diet; or having diabetes or metabolic syndrome. Certain genetic factors also may increase your risk of uric acid stones.
- Cystine stones
This rare type of stone forms because the kidneys leak too much of a specific amino acid called cystine into the urine. They occur in people with a genetic disorder called cystinuria.
The treatment for a kidney stone depends on the size of the stone, what it is made of, whether it is causing pain and whether it is blocking your urinary tract. To answer these and to figure out the right treatment, your doctor might ask you to have a urine test, blood test, x-ray and/or CT scan.
If your test results show that your kidney stone is small, your doctor may tell you to take pain medicine and drink plenty of fluids to help push the stone through your urinary tract. If your kidney stone is large, or if it is blocking your urinary tract, additional treatment may be necessary.
One treatment option is shock wave lithotripsy. After the treatment, the small pieces of the kidney stone will pass through your urinary tract and out of your body with your urine. This treatment usually takes 45 minutes to one hour and may be done under general anesthesia, which means you will be asleep and unable to feel pain.
Another treatment option is ureteroscopy. The doctor uses a long tool shaped like a tube to find and remove the stone or to find and break the stone into small pieces. If the stone is small, the doctor may be able to remove it. If it is large, it may need to be broken into pieces. In this case, a laser will be used to break the stone into pieces that are small enough to pass through your urinary tract.
In rare cases, a surgery called percutaneous nephrolithotomy is needed to remove a kidney stone. During the surgery, a tube will be inserted directly into your kidney to remove the stone. You will be admitted in the hospital for two to three days for surgery and recovery from this treatment.