**2. Hyperthyroidism**

Hyperthyroidism, which is usually due to autoimmune thyroiditis, clinically presents with tachycardia, increased systolic BP, weight loss in spite of increased appetite, and tremors in both hands. The cardiovascular system reveals fast pulse and sometimes irregular pulse known as auricular fibrillation. Auscultation of chest reveals systolic murmur. Neurological examination reveals brisk knee jerk, and patients show anxiety. There is history of diarrhea. In thyrotoxicosis, bone resorption leads to hypercalcemia. There is decreased PTH, decreased urinary, and fecal calcium excretion. There is hyperphosphatemia. Bone mineral density is decreased due to osteoporosis. Forearms are more affected.
