Kidney Stones (Renal Calculi, Nephrolithiasis)

Definition

Solid masses made of crystals that form in the kidneys, potentially causing pain and urinary obstruction.

Patho

Crystals of calcium, uric acid, or oxalate precipitate in the kidney, forming stones that can obstruct the urinary tract.

Etiology

• Imbalances in urine composition (e.g., high calcium, oxalate, uric acid)

• Low urine volume

Clinical Manifestations

• Severe, sharp pain (renal colic), often radiating from the back or side to the groin

• Hematuria

• Nausea/vomiting

• Dysuria

• Frequent urination or urgency

Diagnosis

• Urinalysis (for blood and crystals)

• Imaging (CT scan, ultrasound)

Treatment

• Pain management (NSAIDs or opioids)

• Hydration to facilitate stone passage

• Medications to alter urine chemistry or break up the stone (e.g., thiazides, allopurinol)

• Surgery or lithotripsy for larger or obstructing stones

Complications

• Obstruction and hydronephrosis

• Kidney damage if untreated

• Urinary tract infection

Risk Factors

• Dehydration

• Family history of kidney stones

• High dietary intake of oxalate, calcium, or animal protein

• Obesity

• Hypercalcemia