Parathyroid hormone (PTH) plays an important role in calcium and phosphate regulation. A reverse sigmoidal relationship exists between extracellular calcium levels and PTH secretion. Primary hyperparathyroidism is a state of excess production of PTH by abnormal parathyroid glands. Diagnosis requires a high index of suspicion due to its nonspecific symptoms that require a complete evaluation and workup, thus causing a delay in surgical intervention, from the time of index high calcium levels. A 25-year-old female presented with symptoms of pain over her right knee and easy fatiguability. She had abdominal pain and had visited multiple hospitals since 1 year, and no relief in symptoms. Serum calcium levels were elevated to 12.8 mg/dL, Sr PTH 813 pg/mL, and ALP 3386 IU/L. Bone scan and biopsy revealed osteitis fibrosa cystica of Rt femur with brown tumors in the tibia and mandible. Sestamibi scan showed that the right inferior parathyroid increased tracer uptake. Focused parathyroidectomy was done. Sr PTH levels and Sr calcium levels reached normal levels postoperatively and genetic testing was done as the age of presentation was <35 years. Thus, meticulous examination and workup are cornerstones in diagnosing a case of primary hyperparathyroidism in order to prevent delay in treatment and prevent complications.