This video describes various sleep disorders from insomnia to narcolepsy. [5:26]

This video lesson from Khan Academy and the Association of American Medical Colleges provides study content for the MCAT. This resource discusses breathing-related sleep disorders.

The causes of secondary hypertension are known unlike primary hypertension where the causes are not known. Common diseases that lead to hypertension are renal diseases, pheochromocytoma, sleep apnea, and brain tumors.

This video describes the function of the tonsils and possible reasons for removal (tonsillectomy). [7:53]