Jeffrey W. Olin, DO, FACC, FAHA, MSVM, illustrates his diagnostic thinking during his webinar, “Important Vascular Medicine Concepts for the Cardiologist.” Dr. Olin prefaces his presentation with observations about the effect of COVID-19 on cardiovascular conditions. During the webinar, Dr. Olin presents three cases: a man with swollen legs, a man with a swollen arm, and a woman with fibromuscular dysplasia. In each case, he presents his line of inquiry and diagnostic thinking during the course of examination, as well as possible conditions, complications, and treatments.