Calculus in kidney refers to a kidney stone, which is a hard deposit made of minerals and salts that form inside the kidneys. Kidney stones can affect any part of the urinary tract, from the kidneys to the bladder, and can cause severe pain, nausea, vomiting, fever, chills, and blood in the urine. The development of kidney stones is related to decreased urine volume or increased excretion of stone-forming components such as calcium, oxalate, uric acid, cystine, xanthine, and phosphate. Depending on the size and location of the stone, treatment options may include pain medication, drinking lots of water, shockwave lithotripsy, uteroscopy, percutaneous nephrolithomy, or nephrolithotripsy.