Kidney stones are small mineral deposits formed in your kidneys, also made up of acid salts.
According to Bupa UK Kidney stones are common – five to ten in 100 people are affected by pain associated with kidney stones at some point in their life. Most people who get kidney stones for the first time are aged between 20 and 50.
Most people have two kidneys, which ‘clean’ your blood by filtering out water and waste products to make urine. Kidney stones can form when there’s a build-up of salts or minerals in your urine. These minerals form crystals, which are often too small to notice and pass harmlessly out of your body. However, over time, the crystals can build up inside your kidney to form a kidney stone.
Most kidney stones (about four out of five) are made up of calcium salts (calcium oxalate or calcium phosphate or both). They can also be made up of other substances including uric acid, cystine and struvite. They vary in size from very small stones under 2mm to large ones over 1cm.
Kidney stones may stay where they’re first formed. But they can move out of your kidney into your ureter – the tube that carries urine from your kidney to your bladder. If they get stuck in your ureter, they can cause severe pain, known as renal colic. Depending on a stone’s size and position, it can stop you passing urine easily and lead to infection.
Types of kidney stones
Kidney stones come in a variety of sizes, shapes and colours. Some are like grains of sand, while in rare cases others can grow to the size of a golf ball.
The main types of kidney stones are:
calcium stones, the most common type of stone
struvite stones, usually caused by an infection, like a urine infection
uric acid stones, usually caused by a large amount of acid in your urine.
A person with kidney stones doesn’t experience many symptoms until the stone is moving around in his/her kidney or passes through the ureter, which is the tube connecting the kidney and the bladder. In such cases, amongst the symptoms are :
Severe pain in the side and back, below the ribs and pain in the lower abdomen and groin
Urine that’s pink, red or brown
Urine that smells very foul
Treating and preventing kidney stones
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.
You should contact a GP or NHS 111 immediately if:
you're in severe pain
you have a high temperature
you have an episode of shivering or shaking
you have blood in your urine
Informtion suppied by Bupa, Guts UK and NHS Choices