Select a condition Absence seizures Acne ADHD Age-related macular degeneration AIDS Alzheimer's disease AMD Amebic dysentery Anal tears Angina, stable Angina, unstable Ankle sprain Anorexia Anxiety Appendicitis Arthritis Asthma in adults Asthma in children Athlete's foot Atrial fibrillation Attention deficit hyperactivity disorder (ADHD) Autism Back pain Bacterial vaginosis Bad breath Bedsores Bedwetting Bell's palsy Benign prostatic hyperplasia Bipolar disorder Bladder infection in women Blood pressure Breast cancer Breast pain Bronchiectasis Bronchiolitis Bronchitis Bulimia Bunions Burning mouth syndrome Burns and scalds Canker sores Cardiac arrest Carpal tunnel syndrome Cataracts Cellulitis and erysipelas Chickenpox Childbirth, heavy bleeding Childbirth, tear or cut Chlamydia Chronic bronchitis Chronic fatigue syndrome Chronic obstructive pulmonary disease Chronic prostatitis Chronic tension type headache Cold sores Colic in babies Colon and rectal cancer Colon and rectal cancer screening Colonic diverticular disease Common cold Conjunctivitis Constipation in adults Constipation in children COPD Crib death Deep vein thrombosis Dementia Depression in adults Depression in children Diabetes, type 1 Diabetes, type 2 Diarrhea in adults Diarrhea in children Diverticular disease Ear infection, middle ear Ear infection, outer ear Ear infection with discharge Ear infection with fluid Ear pain during air travel Ear wax Eczema Emphysema Endometriosis Enlarged prostate Epilepsy Episiotomy Erection problems Essential tremor Febrile seizures Fertility problems Fibroids Flu Gallstones Genital herpes Genital warts GERD GERD in children Glaucoma Gonorrhea Gout Group B streptococcus H. pylori infection Halitosis Hay fever Headache, chronic tension type Head lice Heart and circulation problems in diabetes Heart attack Heartburn Heart failure Heavy periods Heel pain Hemorrhoids Hepatitis B Hepatitis C Hernia Herpes, genital Herpes simplex eye infection High blood pressure High blood pressure in pregnancy High cholesterol HIV infection Hyperactivity IBS Incontinence in women Infection in newborn babies Infertility Influenza Insomnia in adults Irritable bowel syndrome Jaundice in newborn babies Jet lag Kidney infection Kidney stones Leg cramps Leg ulcers Lewy body dementia Lung cancer Lyme disease Macular degeneration Malaria prevention Manic depression Mastalgia Measles, mumps and rubella: prevention Melanoma Meniere's disease Meningococcal disease Menopause Migraine in adults Migraine in children MMR prevention Morning sickness Multiple sclerosis Nail infection, fungal Neck pain Nicotine addiction Non-Hodgkin's lymphoma Nosebleeds in children Obesity Obsessive-compulsive disorder OCD Oral thrush Osteoarthritis Osteoporosis Ovarian cancer Painful periods Pancreas cancer Panic attacks Parkinson's disease PCOS Pelvic inflammatory disease Perineal care Peripheral arterial disease Peripheral vascular disease Pneumonia Polycystic ovary syndrome Postpartum depression Postpartum hemorrhage Post-traumatic stress disorder Preeclampsia Pregnancy, nausea Premature birth Pressure sores Prostate cancer Prostatitis, chronic Psoriasis PTSD Raynaud's disease Rectal cancer screening Recurrent cystitis Reflux in children Rheumatoid arthritis Scabies Schizophrenia Seasonal allergy Shoulder pain Sickle cell anemia Sickle cell disease SIDS Sinusitis Skin cancer (melanoma) Skin cancer (squamous cell) Sleep apnea Sleep problems in children Slipped disk Smoking Sore throat Stomach ulcers Stress headache Stress incontinence Stroke, emergency care Stroke prevention Sudden infant death syndrome Swimmer's ear Tennis elbow Tension headache Testicular cancer Thrush (oral) Tic douloureux Tinnitus Tonsillitis Toxoplasmosis in pregnancy Trigeminal neuralgia Underactive thyroid Urinary tract infections in children Varicocele Varicose veins Vascular dementia Warts Whiplash Wisdom teeth, impacted Wrinkles Yeast infection, vagina

Select treatment area Bladder & Kidneys Blood Brain & nervous system Cancer Children's health Diabetes Digestive system Ear, nose & throat Eating & weight Eyes Fertility Heart and circulation Hormones Infections Lungs & breathing Men's health Mental health Mouth Muscles & bones Pregnancy & childbirth Sexual health Skin Sleep Staying healthy Travel health Women's health

Most kidney stones are small enough to work their way out of the body without needing treatment. But if your kidney stone is larger, you may need treatment to get rid of it.

Kidney stones usually vary in size from less than 0.078 inches (2 millimeters) across to more than 0.78 inches (2 centimeters) across. Most of them are less than 0.15 inches (4 millimeters) across -- small enough to pass out of most people's bodies without treatment.¹

If your stone shows up on an X-ray, your doctor might be able to tell you how big it is.

• If it's less than 0.19 inches (5 millimeters) across, you have about a 9 in 10 chance that it will leave your body without treatment.²
• If your stone is 0.19 inches to 0.39 inches (5 millimeters to 10 millimeters) across, you have about a 1 in 2 chance that it will leave your body without treatment. But you should be under the care of a kidney specialist (a urologist).³
• Stones bigger than 0.39 inches (1 centimeter) across rarely pass on their own. If you have a stone this size, you will need treatment to remove it.⁴

It can take two days to four weeks for a stone to pass through your body without treatment.

During this time, you will need to:

• Take strong painkillers to help you cope with the pain
• Drink plenty of water to increase the flow of urine and make it easier for the stone to pass.⁴

To read more, see Treatments to help with pain from kidney stones.

You'll probably be able to stay at home during this time, although you may need X-rays to check on the progress of the stone.

If the pain is very bad, or you're vomiting up fluids, you might have to be watched in a hospital.⁴

You should strain your urine in a tea strainer or something similar to catch any stones, or bits of stones, that pass. This is so that your doctor can find out what type of stone you have and advise you what you can do to avoid getting another one. Your doctor will continue to keep an eye on you until an X-ray shows that the stone has gone.³

If you get more severe symptoms, this may mean your stone is blocking the flow of urine. This can be a serious problem. You should call your doctor right away if you have:⁵

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

You will need to see a urologist if you have a smaller stone that has not passed out of your body within four weeks. After that time, you are more likely to get problems like an infection.³

Until 20 years ago, treatment for removing kidney stones involved a major operation. But now there are much simpler treatments.⁶ You have a good chance of getting rid of your kidney stone if you have one of these treatments.

They include:

• Extracorporeal shock wave lithotripsy (shock wave therapy). This is the most commonly used type of treatment. The doctor uses shock waves to break up the stone
• Percutaneous nephrolithotomy (PCNL). The doctor makes a small cut in your back and passes a needle and a very thin tube into your kidney to remove the stone
• Ureteroscopy. The doctor feeds a fine tube up your urethra, through your bladder and into your ureter to remove the stone.

To read more about these treatments, see What treatments work for kidney stones?

You will probably need to go to a hospital or clinic for these treatments. You might be able to go home the same day, or you might need to stay in the hospital for a few days.

Doctors are advised to use:¹

• Shock wave therapy for small stones in the upper ureters that are 0.39 inches (1 centimeter) across or less.
• Shock wave therapy, PCNL or ureteroscopy for larger stones in the upper ureters
• Shock wave therapy or ureteroscopy for any stones in the lower ureters.

Getting rid of your kidney stone is not the end of the story. You have about a 1 in 2 chance of getting another one within five to seven years.²

Your doctor may carry out some tests on your blood and urine to find out why you got a kidney stone.⁷ Your doctor will also examine your stone to find out what type it is.⁴ (To read about the types of stones, see What are kidney stones?)

Your doctor can prescribe medicines to help stop you from getting some types of stones. The type of medicine you get depends on the type of stone that you've had. The medicines include:⁷

• Types of diuretics (water pills) that reduce calcium in the urine
• A drug called allopurinol that reduces uric acid levels in the blood. The brand name is Aloprim
• Drugs to make the urine less acidic
• Captopril or penicillamine to make cystine (one of the building blocks of protein) less likely to cause stones. The brand name for captopril is Capoten. The brand name for penicillamine is Cuprimine.

We haven't looked at the research on these medicines in the same way as we have for other treatments used for kidney stones (see Our method), so we can't say whether they work.

Your risk of getting more stones is also affected by what you eat and drink. To reduce your risk, you can:⁷

• Drink plenty of water. You can halve your risk of getting a second stone by drinking more than 2 liters (2.11 quarts) of fluid a day
• Eat a healthy diet, including calcium but not calcium supplements. People used to think that calcium in the diet made stones more likely. But now doctors think not eating enough calcium makes stones more likely. Foods rich in calcium include milk, cheese and other dairy products, peas and beans, leafy green vegetables, nuts, and bony fish like sardines and salmon
• Avoid using lots of salt
• Eat more vegetables. Vegetables make the urine less acidic.

If you've had a calcium oxalate stone, you may need to reduce the amount of oxalate in your diet. This means cutting down on chocolate, nuts, rhubarb, strawberries, spinach, coffee and tea.

But changes in diet don't work for everyone and there is not a lot of evidence to show how well they work. So it's important to talk to your doctor before making big changes to what you eat.

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment. ©BMJ Publishing Group Limited 2008. All rights reserved.