Definition: what is a kidney stone
Kidney stones, or “renal calculus”, are little stones that form in the kidneys or urethras. They are crystals formed by minerals (calcium or magnesium) and excess acids in the urine. They can clog up the urinary tracts and cause intense pains. This is known as renal colic.
The size of the kidney stones is variable, and they can measure from a few millimetres to a few centimetres in diameter.
Kidney stones generally appear after the age of 40 and are two times more common in men than in women. They affect around 10% of the population
Symptoms of kidney stones
If the kidney stone is small, it can go unnoticed and pass through urine after a while. However, if the urinary tracts end up obstructed, this can cause various symptoms:
- sharp and intense pains in the lower back radiating towards the belly and the genital areas
- nausea and vomiting
- frequently needing to urinate
- presence of blood in the urine
An episode of renal colic can last between 10 minutes and a few hours.
Complications of kidney stones are rare but if not treated, it can lead to a urinary tract infection or in the most serious cases, septic shock.
Causes of kidney stones
Crystallisation of the salt minerals that form kidney stones can be explained by different reasons. The most frequent is drinking bad water. This is because, this causes a lack of urine dilution and a high concentration of minerals.
A diet that is too rich in sugar or proteins can also cause kidney stones. In rare cases, kidney stones can occur after a metabolic illness (diabetes) or a genetic illness.
Treating kidney stones
In most cases of kidney stones, they pass by themselves after a few weeks. It is recommended to drink around 3 litres of water a day during this period in order to keep well hydrated and help the stone move.
When the renal colic is extremely painful, pain relief medication is necessary in the form of non-steroidal anti-inflammatories or morphine to ease the pain.
The stone can be removed with surgery if they don’t pass on their own. This can be done by a lithotripsy (destruction of the crystal by shockwaves) or by a nephrolithotomy (drainage using a probe).