Kidney stones

Most stones are formed in the kidney and some can then travel down the ureter and into the bladder. Occasionally a stone will form in the bladder itself. If the stone is too large it may become lodged in a ureter. Stones in the kidney or ureter can cause blockage of urine flow or irritation to the urinary tract lining.

There are a number of theories surrounding the formation of kidney stones. Some people also appear to have a tendency toward stone formation for different reasons. Once you have formed a stone, there is an increased risk of you forming more stones.

The known predisposing factors for stone formation are:

• Age
• Sex
• Family history of stone formation
• Chronic dehydration
• Decreased mobility levels
• Certain metabolic diseases
• Occupation
• Diet
• Recurrent or persistent urinary tract infection

Some known causes of stone formation include:

• diseases leading to abnormal crystallisation of urine
• another fragment of stone
• a foreign body e.g. urinary catheter, JJ stent