Monarch Disease Ontology identifier MONDO_0010138 (thyrotoxicosis) is a hypermetabolic syndrome caused by the elevation of thyroid hormone levels in the serum. Signs and symptoms include tachycardia, palpitations, tremor, weight loss, warm weather intolerance, and moist skin. Causes include Graves disease, toxic nodular goiter, toxic thyroid nodule, and lymphocytic thyroiditis.