Hyperthyroidism can be diagnosed based on clinical presentation and lab tests showing suppressed TSH and elevated FT4 and FT3. It is classified as Graves' disease, toxic multinodular goiter, or toxic adenoma based on thyroid antibodies and nuclear scintigraphy. Treatment options include anti-thyroid medications, radioactive iodine therapy, and surgery. Anti-thyroid drugs are first line treatment for Graves' disease, while radioactive iodine or surgery is recommended for toxic nodular conditions. Surgical treatment is reserved for cases where other options are contraindicated or not effective.