Kidney stones can develop in 1 or both kidneys and most often affect people aged 30 to 60.
They're quite common, with more than 1 in 10 people affected.
Kidney stones are usually found in the kidneys or in the ureter, the tube that connects the kidneys to your bladder.
They can be extremely painful, and can lead to kidney infections or the kidney not working properly if left untreated.
You may not notice if you have small kidney stones. You'll usually pee them out without any discomfort.
Larger kidney stones can cause several symptoms, including:
You should contact a GP or NHS 111 immediately if:
Waste products in the blood can occasionally form crystals that collect inside the kidneys.
Over time, the crystals may build up to form a hard stone-like lump.
This is more likely to happen if you:
After a kidney stone has formed, your body will try to pass it out when you pee.
Most kidney stones are small enough to be passed in your pee, and it may be possible to treat the symptoms at home with medication.
Larger stones may need to be broken up or removed with surgery.
It's estimated up to half of all people who have had kidney stones will experience them again within the following 5 years.
To avoid getting kidney stones, make sure you drink plenty of water every day so you do not become dehydrated.
It's very important to keep your urine pale in colour to prevent waste products forming into kidney stones.
The kidneys are 2 bean-shaped organs that are roughly 10cm (4 inches) in length.
They're located towards the back of the abdomen on either side of the spine.
The kidneys remove waste products from the blood. The clean blood is then transferred back into the body and the waste products are passed out of the body when you pee.