Hypertension Specialty


The Hypertension Clinic at SIU Medicine specializes in the diagnosis and treatment of patients with hypertension, or high blood pressure. Our multidisciplinary team has extensive training with patients who have difficult to treat blood pressure, or resistant hypertension.

According to the CDC, in 2021 high blood pressure was a primary or contributing cause in over 690,000 deaths in the United States. But only about 1 in 4 adults with hypertension have their blood pressure under control. The SIU hypertension team uses cutting-edge testing, prescriptions, over-the-counter medications, and lifestyle changes to lower blood pressure. Patients can refer themselves to the clinic or be referred by their doctor.

Dr. Flack with patient


  • 24-hour ambulatory blood pressure monitoring
  • Workup of secondary causes of hypertension
  • Lifestyle assessments, including sleep apnea, BMI, and diet
  • Diagnosis and management of renal vascular hypertension
  • Innovative clinical research

Clinic goals

“Our goal is to assist our patients in achieving lower blood pressure with the fewest possible number of medications, manage resistant hypertension and identify diet and exercise programs that may help better control high blood pressure and maximize our patients’ health,” said John M. Flack, MD, MPH, director of the hypertension clinic and professor and chair of the Department of Internal Medicine. “Whether patients are referred to us by a specialist or their primary care physician, or they simply decide on their own that they need additional help controlling their blood pressure, we are dedicated to providing our patients with the best options for treatment – in partnership with their current physician team.”

Flack is an American Society of Hypertension (ASH)-certified clinical hypertension specialist and serves as the vice president of the ASH Hypertension Specialist Board. Among his many honors, he has been repeatedly named a “Top Doctor” by the Who’s Who Global Directory and Academic Physician of the Year by Oklahoma University School of Medicine. In 2009, Detroit News named him Michiganian of the Year.

John Flack
Clinical Trials

Learn more about our hypertension research

The hypertension team conducts cutting-edge research to explore new treatments for high blood pressure. Learn more and see if you are eligible to participate.