Kidney Stones

Typically, stones are formed in the kidneys and may go undetected. Urinary stone disease is a significant health problem. Formation of stones in the urinary tract is called urolithiasis. This causes an acute painful condition called renal colic. It strikes without warning at any time and the pain is often described as worse than labor pain.

Incidence

Men are affected by renal stones more commonly than women. The male-to-female ratio is approximately 3:1. It occurs commonly between 30-50 years of age. Approximately 80-85 per cent of stones pass spontaneously without any long term sequelae. Patients who experience an initial urinary stone are likely to form further stones in the lifetime unless they can modify their risk factors for urinary stone formation.

Urinary Stones, or “calculi”, occur due to abnormal and excessive accumulation of substances such as calcium, oxalate, uric acid and cystine in the urine. Usually, these substances are dissolved in the urine by the presence of substances such as citrate and pyrophosphates. The formation of stones is a complex process and depends on the various factors which include:

Changes in urinary pH or acidity.

Dehydration - Stones arise when urine becomes supersaturated with salts and crystals that are capable of forming stones.

Inadequate urinary drainage - slow obstructive urine flow will encourage salt precipitation due to stagnation.

Hyperparathyroidism leads to increased calcium in urine.

Increased intake of vitamin D and calcium.

Prolonged immobility due to hypercalciuria as calcium is lost from the bones.

Metabolic disorders such as renal tubular acidosis, malabsorption and hyperuricemia.

Hereditary disease such as cystinuria.

Underlying disease of the small bowel.

Urinary tract infection

Symptoms

Many stones are asymptomatic until they begin to move down the ureter, causing pain due to obstruction. The main symptoms of renal colic are:

Pain - The most common symptom of kidney stone is severe back or abdominal pain.

Nausea, vomiting, excessive sweating

Hematuria or blood in the urine.

Urinary tract infection-symptoms may include fever, chills, sweats and pain with uriniation.

Small, minimally symptomatic stones often pass spontaneously and can be managed conservatively. Severe symptoms, obstructing stones or the presence or urinary infection warrant intervention, often emergently. The presence of stones can only be detected by radiographic evaluation, typically a CT scan. Many types of intervention are available for stone disease including temporary stents, ureteroscopy, shock wave lithotripsy and surgical procedures to remove larger stones.