This document summarizes various disorders of blood vessel hyperreactivity and tumors. It describes Raynaud phenomenon which results in vasoconstriction of arteries and arterioles. It also discusses myocardial vessel vasospasm which can lead to Prinzmetal angina or myocardial infarction. Varicose veins, thrombophlebitis, and superior/inferior vena cava syndromes are also outlined. Finally, it provides details on various benign and malignant vascular tumors including hemangiomas, lymphangiomas, and Kaposi sarcoma.