<prompt> All are true about primary hyperparathyroidism except -NephrolithiasisIncreased alkaline phosphataseDecreased calciumLoss of lamina dura  <response>: Ans. is c i.e., Decreased calcium Clinical features of HyperparathyroidismSymptomatic signs and symptomsAsymptomatico Recurrent nephrolithiasiso Peptic ulceration abdominal paino Extensive bone resorptiono Mental changes; Psychiatric manifestationsManifestation may be subtle and the disease many have a benign course with no symptoms and signs other than Hypercalcemia and elevated level of PTHSubtle presentation may simulate asymptomatic hypercalcemia . Bone in HyperparathyroidismHealing responseResorptiono Osteitis fibrosa CysticaDistinctive bone manifestation Characterized by replacement of normal cellular and marow elements by fibrous tissueOther Manfestationso Absence of lamina durao Pinhead stippling of skullo Marrow fibrosiso Diffuse bone Resorptiono Subperiostal bone resorption of phallangeal tuftso Brown tumor of hvperparathvroidism well circumscribed dark brown area in the region of severe bone resorptiono Osteoporosiso Deformityo Pathological fracturesMarkers of Hyperparathyroidism ed PTH:1. Increased serum calcium Stimulates Vit D which causes increased absorption of Ca from gut Increased calcium reabsorption from tubules Increases osteoblastic activity in bones and mobilizes calcium from bone into serum.2. Decreased serum phosphorus PTH acts on tubules to increase excretion of phosphorus3. Increased 24 hr urine calcium Despite increased reabsorption of Ca in renal tubules urinary calcium is increased owing to increased filtration of calcium in glomerular filtrate.4. Increased alkaline phosphatase Increased resorption of bone leads to compensatory elevation of osteoblastic activity.5. Radiological changes : Subperiosteal resorption of phalanges is characteristic hand X Rays are always advised. Bone resorption i.e., osteitis fibrosa et cystica brown tumours Loss of lamina dura 