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Dr Tania Dempsey new office westchester


My mission is to prevent chronic disease. I specialize in getting to the “root” of the root cause of your illness. Patients come to me from all over the world who cannot get a definitive diagnosis from other doctors. As an expert in mystery illnesses, I focus on the story behind the symptoms.


My goal is to help patients understand the role the toxic environment is playing in our health and to learn how to find ways to cope with it through functional medicine.

Why I Opened my Practice.. 

I was increasingly frustrated with the limitations that were placed on me in the practice I was with.  I felt suffocated by the traditional medical model.  I was discouraged from trying to help patients get better "holistically."   I was reprimanded for spending too much time with patients and for not using statin drugs to lower cholesterol levels.  Because I used lifestyle modification and knew the data did not support the relationship between cholesterol and heart disease, my patient's cholesterol numbers did not meet the range dictated by insurance companies.

So, I decided to take things into my own hands.  I wanted to create a patient-centered practice where healing begins the minute they walk through the door. I wanted to be able to explore many treatment options for the patient (from east to west), and not just what big pharma was saying to do.  I wanted to give patient's the attention they deserved, and to have the time to educate them.  I knew that I could create the "optimum" environment for optimum health.

My Philosophy.. 

I've always been driven to treating patients who are unable to get answers about their health from other doctors. I refer to the phenomena as “mystery-illness” patients. These patients have complex, chronic illnesses that no one else has been able to figure out. This has become my niche and I believe that is because I think outside the conventional box of medicine. I know that these patients are sick and I know there's something wrong, and I desperately want to figure it out for them. 


While I’ve always been passionate about helping patients get to the root cause of their illness, my practice and understanding of the human body has evolved through my personal experiences.


When I first started my integrative medicine practice nine years ago, I was introduced to Dr. Richard Horowitz, when we spoke at a conference together. I was overwhelmed, in a good way, by the information that he presented, and I vividly remember the conversation I had with him afterwards. He knew that I was practicing in Westchester County, NY, a suburb of New York City, which is endemic for Lyme disease. 


He said to me, “Well, you must see a lot of Lyme disease in your practice,” and I recall saying, “I have a few cases”, and he said, “No, you don't. You're not looking, and you're not thinking about it enough.” I stood there a bit taken aback thinking that he must be wrong. 


The next day I was back in my office seeing patients and started thinking about what he said.  As the weeks and months went by, I tried to keep an open mind about the patients I was seeing and started to question whether their “mystery cases” could be explained by tick-borne infections.  


I went back over the cases that I couldn’t figure out and re-reviewed the medical history of these patients and I slowly chipped away at it until I got a clearer picture of what the root cause(s) of their illness were. Bingo! 


Many of these patients had Lyme, Babesia, Bartonella, or other insect-borne infections that no one else had found.  With treatment, many of these patients who previously could not get better did.  That next year or two was life-changing for my patients. Once I started seeing it, then I started seeing it. 


A couple of years later, Dr. Horowitz and I were speaking at another Lyme disease conference together and I asked him if he remembered what he said to me. He just nodded and smiled as I told him that he was absolutely right.  There was no question that I had many more patients with Lyme and co-infections than I previously thought and I estimated that 70-80% of them either had or were currently suffering the consequences of tick-borne infections. Once I got it and truly understood this piece of the puzzle in many of my chronically ill patients, it changed everything.


It turns out that around the same time, several members of my family were infected with Lyme disease. 

Thankfully, I was tuned into it already, and I knew what to do. Over time, however, it became clear that some family members and some patients were not getting better, despite aggressive treatment. 


At that point, many Lyme literate physicians, including myself, started appreciating that treatment for all co-infections was critical and if patients were only treated for Lyme they often relapsed.  It also quickly became clear that some patients weren’t getting better because of the persistence of these organisms that antibiotic treatment didn’t eradicate. More importantly, it became evident that some patients were not getting better, not because of the infections, but because of a dysregulation of their immune system, particularly the mast cells. 


In 2014, I officially diagnosed my first patient with mast cell activation syndrome (MCAS), and this led to an opportunity to connect with Dr. Lawrence Afrin, who was known at that time, and still is, as one of the world’s experts in MCAS. My conversations with Dr. Afrin from 2014 through 2017 were incredibly meaningful and set me on a career path that I would never have anticipated.


Gaining an understanding of MCAS and its role(s) in multisystemic diseases was truly a pivotal point in my career. I realized very quickly that this was an even bigger piece of the chronic disease puzzle and I needed to do everything in my power to further our knowledge of the disease.  In 2017, when Dr. Afrin joined my practice, we also merged in our vision for the future of MCAS.  


As we now approach the opening of our new center in Purchase, NY, our vision is coming to fruition in 2020. The center will be dedicated to the highest standards of medical care, research and education. I am hopeful that a paradigm shift in the care of patients with complex, chronic illnesses is imminent.

Medical Focus.. 


I treat patients with complex, chronic multi-systemic diseases that other doctors can’t figure out. Many of the patients that I see carry different diagnoses.  The common theme across all of the diseases I treat is multi-systemic immune dysregulation.  


Maybe you have been all over the country (and world) trying to get answers to the medical illness you suffer with that has affected your life on so many levels. 


My mission is to help you get to the root cause and figure out what is really driving your medical issues and then help you recover with a protocol and personalized treatment plan.  


Mystery Illness Specialist..


I consider the conditions that patients come to me with as mystery illnesses. 


Have you been told that…


A.      It’s in your head.

B.      You are making things up. 

C.      You are imagining symptoms. 


If so, you’re not alone. You really have these symptoms and you are affected by them daily. Even though your medical symptoms may not make sense to traditional doctors looking to check off a box, they make sense to me. I am here to validate how you feel and get to the root cause of why you feel the way you do to help you feel better. 


Maybe you have been discounted in the traditional medical world.


According to the medical books, your symptoms don't fit the algorithms that doctors use and so if they don't fit, then they really are a mystery illness and they need somebody who can look at it and say, how do the pieces fit together? I help you fit it together. 


Often, it's not a mystery and at the end of the day, we figure it out, together. But many people think you are a medical mystery because other doctors haven't been able to figure it out or you haven't given the time to the patient to figure it out. That changes starting today. 


You go through life and think things are okay.  Everyone has a random medical issue that pops up, but with the patients I treat, when something pops up, it's not clear why. Sometimes there is a trigger that you can look back at and say, ‘Oh, that was what happened and that probably led down this path.’ But often it's coming out of the blue and your health deteriorates and there really is little control. Maybe you have tried to find ways to control it. Sometimes it feels like you can't and that's frustrating and heartbreaking. That is why I've dedicated my career and my life to figuring out the most difficult of medical cases and helping patients like you regain control of your life again. 


My Approach..


The patient-doctor relationship is sacred and we work together as a team. I'm not paternalistic in telling you what you need. You know your body better than I know your body. If you tell me that you think you don't need medication, but you know you need something else, let's work together to figure out what that is.




You have to listen to your gut instinct because others don't know your body as well as you do. Listen to that voice. If you've had a symptom, if you feel something and others are discounting it, if you feel that it's real, and you know it in your gut, then listen to it and try to find someone who can help you. 

A more holistic approach to your health

A detailed approach to multi systemic diseases

Patient Growth:

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