John Flack, MD

Internist, specializing in hypertension
Internal Medicine
Accepting new patients
Call for an appointment

    About me

    Professional Service
    • Vice President, American Society of Hypertension (ASH) Specialist Board 2014 – present
    • Member, AHA Scientific Statement Writing Group on Resistant Hypertension 2016 – 2017
    • Member, AHA Research Strategic Outcomes Committee 2017 – present
    • Member, National Institutes of Health (NIH) Institutional Training Mechanism Review Study Section 2014 – 2018
    • Member, Psychosocial Risk and Disease Prevention Study Section, Office of Behavioral and Social sciences Diseases (NIH) 2007 – 2011
    • President, International Society on Hypertension in Blacks (ISHIB) 2001 – 2001
    • Past member, Food and Drug Administration (FDA) Cardio-renal Advisory Panel

    Editorial Boards

    • Associate Editor, American Journal of Hypertension 2016 – present
    • Associate Editor, Cardiorenal Medicine
    • Editorial Board member, Metabolic Syndrome and Drug Therapy
    • Editorial Board member, Journal of Endocrine Disorders
    • Editorial Board member, Journal of Clinical Nephrology and Research
    • Annals of Clinical and Experimental Hypertension
    • Journal of Endocrinology, Diabetes and Obesity
    • British Biotechnology Journal
    • Advances in Combination Treatments for Hypertension
    • Journal of Diabetes Research and Clinical Metabolism (JDRCM)
    • Clinical and Experimental Pharmacology and Physiology
    • Kidney and Blood Pressure Research
    • CardioRenal Medicine
    • Integrated Blood Pressure Control
    • Therapeutic Advances in Cardiovascular Disease
    • Journal of Clinical Hypertension
    • Current Cardiovascular Reports
    • Current Hypertension Reviews
    • Internal Medicine/Cardiology News


    Remote video URL



    Education & training

    Professor and Chair, Department of Internal Medicine
    Board Certifications
    Clinical Hypertension
    Internal Medicine
    Medical School
    University of Oklahoma School of Medicine, Oklahoma City, OK
    Undergraduate Degree
    Langston University, B.S., Chemistry (Math Minor),1978
    University of Oklahoma School of Public Health, MPH, 1988
    University of Minnesota School of Public Health, MPH Epidemology, 1990
    University of Oklahoma Health Sciences Center, Oklahoma Memorial Hospital, Oklahoma City, OK
    Chief Resident, 1985-1986
    Postdoctoral Research Fellow, (Cardiovascular Epidemiology) National Heart Lung and Blood Institute, 1990
    American Society of Hypertension (FASH), Fellow - 2012


    Clinical locations


    SIU Internal Medicine Clinic

    751 N. Rutledge St. Springfield, IL 62702 Suite 1100
    Mon: 7:00 am-4:30 pm
    Tue: 7:00 am-7:00 pm
    Wed: 8:00 am-4:30 pm
    Thu: 7:00 am-7:00 pm
    Fri: 7:00 am-4:30 pm

    Hospital privileges

    • HSHS St. John's Hospital, Springfield, IL
    • Memorial Health, Springfield IL


    Research Interests

    Clinical trials

    Internal Medicine

    REFRESH: A Phase 3, Double-blind, Placebo-controlled and Open-label Efficacy and Long-term Safety Study of Firibastat (QGC001) Administered Orally, Once Daily, for Up to 48 Weeks in Patients with Difficult-to-treat/Resistant Hypertension

    Active recruiting

    PURPOSE: The purpose of this clinical trial is to assess the effects of firibastat on blood pressure, in patients with difficult-to-treat and/or treatment-resistant hypertension

    Internal Medicine

    RADIANCE Continued Access Protocol (CAP): A study of the ReCor Medical Paradise System in Clinical Hypertension

    Active recruiting

    PURPOSE: This purpose of this clinical trial is to find out if a medical device called the Paradise Renal Denervation System
    can lower blood pressure in patients who have hypertension


    Family healthcare advocate Integrated with medical Specialists to improve cardiometabolic Health (FISH)

    Active recruiting

    The purpose of this study is to evaluate the impact of a Family Healthcare Advocate in management of Type 2 Diabetes and Hypertension among SIU Medicine Endocrinology patients residing in Springfield, IL zip codes 62702 and 62703.