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 2 millimetres across to more than 2 centimetres across. Most of them are less than 4 millimetres across, so they're small enough to pass out of people's bodies without treatment.
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 5 millimetres across, you have about a 9 in 10 chance that it will leave your body without treatment.
If your stone is 5 millimetres to 10 millimetres across, you have about a 5 in 10 chance that it will leave your body without treatment. But you should be under the care of a kidney specialist (a urologist).
Stones bigger than 1 centimetre across rarely pass on their own. If you have a stone this size, you will need a procedure to remove it.
If you don't need a procedure to remove the stone
It can take two days to four weeks for a stone to pass through your body.
During this time, you will need to:
To read more, see Treatments to help with pain from kidney stones.
If you have a stone stuck in a ureter, your doctor might also recommend taking a medicine called an alpha-blocker. This type of drug is often used to treat high blood pressure or symptoms of an enlarged prostate, but studies show it can also help stones to pass through the ureters faster. To learn more, see Treatments to remove 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 looked after in hospital.
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 about 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.
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 straight away if you have:
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
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.