Dr. Cushman graduated magna cum laude from the University of Mississippi School of Medicine, where he was also selected to the Alpha Omega Alpha honorary society in his third year. He completed his residency training at the University of Mississippi in Jackson and served on the faculty from 1977 to 1988, when he moved to the University of Tennessee in Memphis.

Dr. Cushman has been an investigator in many clinical studies relating to hypertension and lipid therapy. He has been the chairman for two VA Cooperative Studies: 1) PATHS (Prevention and Treatment of Hypertension Study), a multi-center clinical trial examining the effects of reducing alcohol intake on blood pressure in heavy drinkers, and 2) the VA participation in the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), a National Heart, Lung and Blood Institute (NHLBI) study comparing cardiovascular events from four major classes of anti-hypertensive agents in over 42,000 patients. He is also principal investigator for the VA Clinical Center Network of the NHLBI-sponsored Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial (2000-2008).

Dr. Cushman's research is focused on: drug treatment and lifestyle changes in the prevention and management of hypertension and lipid abnormalities; prevention of cardiovascular outcomes; and cardiovascular disease epidemiology. The types of trials he is involved with include: morbidity and mortality outcomes, efficacy, compliance, predictors of response, hypertension in special populations and intermediate endpoints. Areas of research in lifestyle changes (non-drug therapy) include exercise, alcohol intake, sodium intake, potassium intake and weight loss.

Dr. Cushman was also a member of the writing team for JNC VI. He is a member of the Executive Council of the American Society of Hypertension, where he also serves as treasurer.