The intent of this lecture is to provide a comprehensive overview of headaches and migraines.  The presenter discusses the importance of obtaining headache history, symptoms and red flags, assessment and diagnostic testing, and treatment of headaches.  The presentation will review primary versus secondary headaches, thunderclap headaches, subarachnoid hemorrhage (SAH), cerebral venous sinus thrombosis (CVST), dissection, Reversible Cerebral Vasoconstriction Syndrome (RCVS), Idiopathic Intracranial Hypertension (IIH), intracranial hypotension, and trigeminal neuralgia. Finally, the presentation will review medication overuse in the treatment of headaches and migraines.