article_snippet.sent: two large stones start causing pain - known as renal colic - once two large stones travel down the ureter, the narrow tube that carries urine from the kidney to the bladder. '
article_snippet.sent: Renal colic is caused by the stone suddenly blocking the ureter,' says Mr Leye Ajayi, consultant urological surgeon at the Hospital of St John & St Elizabeth, London.
article_snippet.sent: Sometimes, if a stone blocks the exit of urine from the kidney, it can lead to a build-up of bacteria and trigger a kidney infection.
article_snippet.sent: The main cause of kidney stones is dehydration. '
article_snippet.sent: But if you become dehydrated, you overload Your kidneys with urine that has a high concentration of stone-forming chemicals, and these begin to bind together to build stones.'
article_snippet.sent: This can lead to uric acid stones forming, especially if you also don't drink enough fluid to assist the kidneys in their disposal job.'
article_snippet.sent: So the more salt you eat, the more calcium you will have in your urine, which can build into stones.
article_snippet.sent: This causes a change to the nature of urine, making a change to the nature of urine more acidic, which increases the risk of uric acid stones forming in the kidney.
article_snippet.sent: Eating excessive amounts of oxalate is another culprit, as it can lead to the formation of calcium oxalate stones - the most common kind.
article_snippet.sent: If you have more than two urinary tract infections within a short space of time, you should ask your GP for an ultrasound to rule out a less common kind of kidney stone called struvite stones, which are caused by a build-up of bacteria from repeated urinary tract infections, adds Dr Griffith.
article_snippet.sent: Mr Ajayi also recommends drinking water with lemon juice in Mr Ajayi daily, as the citrate (a form of acetic acid) in lemons is a natural stone inhibitor that can prevent calcium from binding with other substances, such as oxalates, that lead to stones.