Our Location

      503 Avenue A,
      Suite 1118
      San Antonio, TX 78215

      About Us

      Root Causes Medicine

      Root Causes Medicine is a functional medicine practice devoted to discovering the underlying causes of complex illness. Put simply, we search for the answers to the question, “Why?”

      • “Why am I so tired?”
      • “Why did I get this condition so many others have never even heard of?”
      • “Why do I have intractable pain?”
      • “Why must I take 10 pills a day?”
      • …and many others.

      All of the providers at Root Causes Medicine are certified functional medicine practitioners committed to developing an individualized health plan for each new client searching for answers to these questions.

      The good news is that there is often an answer and there is often something that can be done to relieve the symptoms, slow the progression, or reverse the disease process.

      The hard news is that the road to healing is often long, arduous, and filled with potholes.

      • It always requires a lot of work…
      • Ongoing work…
      • A lot of careful thought…
      • Ongoing careful thought…
      • A substantial commitment to a long and tedious process.
      • It also requires making difficult choices, daily and repeatedly.

      And, healing cannot be accomplished with any number of medications prescribed during a 10 minute office visit, no matter how many times that happens every year. Patients who have been successful have agreed that their improvement is worth the work.

      To see if we can help you get your health back, please give us a little information about yourself in the contact form below.

      Meet the Practitioner


      Derek W. Guillory, MD


      Derek W. Guillory, MD, our founder and Medical Director, earned his Bachelor of Science in Education at Baylor University in 1997, graduating Magna Cum Laude. In 2001, he graduated from the University of Texas Southwestern Medical Center in Dallas. He continued his medical training in Emergency Medicine at UT Southwestern Medical Center, graduating in 2004. He has been continuously Board Certified by the American Board of Emergency Medicine since 2005.

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