Kidney stones

Overview

Kidney stones form when minerals like calcium, oxalate, and uric acid build up in the urine and stick together. They can be as small as a grain of sand or much larger.

A stone often causes no pain until it moves into the tube that drains the kidney. Then it can block urine and cause severe pain. Kidney stones rarely cause lasting damage if treated, but they often come back.

Symptoms

Small stones may cause no symptoms at all.

• Sharp pain in the side (flank) or back
• Pain that comes and goes in waves
• Pain that moves to the lower belly or groin
• Pink, red, or brown urine (blood in urine)
• Nausea

Less common

• Vomiting
• Burning or pain when peeing
• Needing to pee often
• Cloudy or bad-smelling urine
• Fever and chills (a sign of infection)

How it usually goes

• Sudden: Severe pain starts when the stone moves.
• Days to weeks: Small stones often pass on their own.
• Years later: Stones often come back without prevention.

Look up a symptom: Back pain · Belly pain spreading to the back · Burning when urinating · Nausea · Pink, red, or brown urine (blood in urine) · Side (flank) pain · Vomiting

When to get medical care

Causes

Stones form when urine has high levels of minerals like calcium, oxalate, phosphorus, or uric acid.

The biggest cause is not drinking enough fluids. Diet, weight, some health problems, and family history also play a part.

Does it spread or run in families?

• It isn't caught from someone else. It's caused by germs that already live on or in the body.
• It can run in families. Tell your doctor if a parent, brother, or sister has it.

Who is more likely to get it

• Not drinking enough fluids
• Past kidney stones or a family history
• A diet high in salt or animal protein
• Being overweight
• Hot weather or heavy sweating

Possible complications

• Kidney infection: A stone can trap infected urine
• Urinary tract infection: Can come with a stone
• Dehydration: From vomiting

Diagnosis

A healthcare professional asks about your pain and orders tests to find the stone.

Questions you may be asked

• Where the pain is and whether it comes in waves
• Blood in your urine or pain when peeing
• Fever, chills, nausea, or vomiting
• Past kidney stones
• How much you drink each day

The exam

They'll press on your belly and back to check where it hurts.

Tests

Tests often include:

• Urine test: To look for blood, crystals, and infection.
• CT scan or ultrasound: To find the stone and see its size and place.
• Blood tests: To check kidney function and mineral levels.
• Stone analysis: If you catch the stone, a lab can tell what it's made of.

Treatment

Treatment depends on the stone's size and where it is. Small stones often pass in a few days to weeks.

Self-care

• Drink lots of water, unless told otherwise, to help the stone pass
• Take pain medicine as directed
• Pee through a strainer to catch the stone so it can be tested
• Stay active if you can

Medicines

Medicines can ease pain and help stones pass or prevent new ones.

Being pain-free doesn't always mean the stone has passed. Follow up as directed.

Larger stones, stones that block urine, or stones with infection may need a procedure. Options include shock waves to break the stone up, or a thin scope to remove it. If you're vomiting and dehydrated, you may need IV fluids.

How it compares

Prevention

Drinking enough is the most important step:

• Drink 6 to 8 glasses of fluid a day, more in hot weather; water is best
• Aim for light-colored urine
• Eat less salt and limit meat
• Citrus drinks like lemonade may help
• Don't cut out calcium from food unless told to; ask about supplements

Which doctor treats this

• Start with your primary care provider (family doctor or internist).
• They may send you to a urologist (urinary tract doctor).

Living with it

Support groups and helplines

• National Kidney Foundation: Help line, peer mentors, and education about kidney health.

Children, pregnancy, and older adults

• Children: Kids can get stones too. A child with kidney stones should drink plenty of water unless told otherwise.
• Pregnancy: Get checked for any side pain or blood in urine. Some tests and medicines are avoided.
• Older adults: Ask before using ibuprofen for pain if you have kidney or heart problems.

Pregnancy and breastfeeding

• If you're pregnant or planning to be, tell your prenatal provider about this condition.
• This condition needs closer checkups during pregnancy. Plan ahead with your doctor.
• Some infections can pass to the baby during pregnancy or birth. Tell your provider if you've been exposed.
• Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
• Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
• Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.

Outlook

Kidney stones are painful but usually pass or are removed without lasting damage. They often come back, so prevention matters.

Getting ready for your visit

Bring the stone if you caught it.

What to bring

• The stone, in a clean container
• A list of medicines and supplements, including calcium and vitamin C
• How much you drink in a day

Questions to ask

• What type of stone is it?
• Will it pass on its own?
• Do I need a procedure?
• What can I eat or drink to prevent more?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Kidney stones