hyperplasia)Vitamin D toxicitySecondaryImmobilizationTertiaryThiazide diureticsFamilial hypocalcsuric hypercalcemiaGranulomatous disease (sarcoidosis)Symptomatic Primary HyperparathyroidismThe signs and symptoms of hyperparathyroidism reflect the combined effects of increased PTH secretion and hypercalcemia.Classical description of symptoms in Primary hy perparathy roi d i smPainful bonesRenal stonesAbdominal groansPsychic moansThe constellation of symptoms includes:Bone disease and bone pain secondary to fractures of bones weakened by osteoporosis or osteitis fibrosa cystica.Nephrolithiasis (renal stones) in 20% of newly diagnosedpatients, with attenoant pain and obstructive uropathy. Chronic renal insufficiency and abnormalities in renal function lead to polyuria and secondary polydipsia.Gastrointestinal disturbances, including constipation,nausea, peptic ulcers, pancreatitis, and gallstones.Central nervous system alterations, including depression,lethargy, and eventually seizures.Neuromuscular abnormalities, including weakness andfatigue.Cardiac manifestations including aortic or mitral valve calcifications (or both).SECONDARY HYPERPARATHYROIDISMIt is caused by any condition that gives rise to chronic hypocalcemia, which in turn leads to compensatory overactivity of the parathyroid glands.CausesRenal failure is by far ihe most common cause of secondary hyperparathyroidismInadequate dietary intake of calciumSteatorrheaVitamin D deficiencyThe eliopathogenesis is complex and not fully understood.Chronic renal insufficiency is associated with decreased phosphate excretion, which in turn results in hyperphosphatemia.The elevated serum phosphate levels directly depress serum calcium levels and thereby stimulate parathyroid gland activity.In addition, loss of renal substance reduces the availability of a-1-hydroxylase necessary for the synthesis of the active form of vitamin D, which in turn reduces intestinal absorption of calcium Because vitamin D has suppressive effects on parathyroid growth and PTH secretion, its relative deficiency compounds the hyperparathyroidism in renal failure.">