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Center for Complex Diseases

Specializing in Chronic Fatigue Syndrome/Myalgic 
Encephalomyelitis, Dysautonomia, Long Covid, Mast Cell Activation, Autoimmune Diseases, Chronic Infections​


At the Center for Complex Diseases, we believe in the need to understand the interplay of the immune system, and its effect on patient health. Our personalized, multifaceted treatment aims to understand the myriad factors responsible for chronic complex diseases and design treatment plans based on patient history, laboratory data, and differential diagnosis. 

All our doctors at CCD are working members of the U.S. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Clinical Coalition and part of the Guideline Committee. They have helped write the consensus recommendations published in the Mayo Clinic proceedings -

Our Doctors

 Bela Chheda, MD

After completing a 3-year residency program in Internal Medicine at The University of Southern California  in 2002 she worked at Kaiser Permanente Urgent Care in San Rafael, CA. 


From 2003-2005, Dr. Chheda completed an Infectious Disease Fellowship at USC Medical Centers including the USC University Hospital, Los Angeles County Hospital, Norris Cancer Hospital and the Rand Schrader HIV Clinic.  Dr. Chheda received her Board Certification in Infectious Diseases in 2005 and was recertified in 2015.  She is also Board Certified in Internal Medicine. 

From 2005 - 2016, Dr. Chheda practiced Infectious Diseases in the Easy Bay of California covering the hospitals of John Muir, Mt. Diablo, and Sutter Antioch. During this time, she began recognizing an increasing gap between patient diagnosis, and the limited explanations offered by traditional medicine for many chronic illnesses. An increasing number of patients with unexplained symptoms, lead her to expand her horizons into ME, and channel her energies into wanting to help these patients who were often misdiagnosed.

In 2015, this led her to the Open Med Institute, where Dr. Chheda specialized in seeing patients with Chronic Fatigue Syndrome. Dr. Chheda's background in Infectious Diseases is particularly valuable in cases of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) which can be  related to the complex interplay of infection and the immune system. 

In 2017 Dr. Chheda and Dr. Kaufman together opened the Center for Complex Diseases. There is a focus on patients suffering from ME/CFS, Dysautonomia, Autoimmune Diseases, Chronic Infectious Diseases, Small Intestine Bacterial Overgrowth Syndromes, and Mast Cell Activation Syndrome. She is a member of the ME/CFS Collaborative Research Center at the Stanford University Genome Technology Center and an active participant in several national clinician networks that focus on ME/CFS, Mast Cell Activation Syndrome, and Autoimmune Disease. 


Dr. Chheda is currently a working member of the U.S. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Clinical Coalition and part of the Guideline Committee. She helped write the consensus recommendations that has been published in the Mayo Clinic proceedings -  

David Lyons Kaufman, MD

After earning a BFA from New York University School of the Arts in Filmmaking, an MA from Teachers College, Columbia University in Education, and his MD from New York Medical College, Dr. Kaufman completed his Internal Medicine Residency training at St. Vincent’s Hospital and Medical Center in New York City.  

He began his Internal Medicine practice in Greenwich Village in NYC just as the epidemic that came to be known as HIV/AIDS exploded.  With St. Vincent’s at the epicenter of this outbreak, he became deeply involved in the care of HIV positive patients and in the research aimed at discovering ways to treat both the opportunistic infections they were dying from and the virus that was causing the destruction of their immune systems.     

As HIV/AIDS became a treatable chronic infection, the practice expanded to include more primary care/general internal medicine patients ranging from 18-105 years old. He also became involved in the diagnosis and treatment of a variety of chronic, often difficult to diagnose and manage conditions, such as Lyme disease, Fibromyalgia, Chronic Viral diseases, vitamin and nutrient deficiencies.     

During the course of his 32 years in practice in NYC, he has been privileged to provide primary care to multiple family generations and to a widely diverse population of patients.  He was responsible for and coordinated the full range of their care, both in the office, in the hospital, and with other consulting physicians. 

In addition to his private medical practice, he was the Medical Director for one of the largest HIV Centers in the New York State, the Director for HIV Clinical Research at St. Vincent’s, and, for several years, Senior Vice President for Network Development at the 7 hospitals that made up the St. Vincent’s hospital system.   As an Attending physician at St. Vincent’s and a teacher of medical students and residents both at the hospital and at the medical school, he received many accolades including being honored by the entire Medical Staff.  Over his many years of practice he was consistently cited in the New York Magazine listing of Best Doctors in New York and has been recognized by the Castle Connolly listing of Top Doctors: New York Metro Area from 1998-2012.    

In 2012, he moved to California and joined Open Medicine Institute where he was the Medical Director of the Open Medicine Clinic, managing the staff and providing the majority of clinical services to patients. In 2017, he opened a new clinic, the Center for Complex Diseases, with a focus on patients suffering from ME/CFS, Dysautonomia, Autoimmune Diseases, and Chronic Infectious Diseases including Tick borne diseases, Small Intestine Bacterial Overgrowth Syndromes, and Mast Cell Activation Syndrome. He is a member of the ME/CFS Collaborative Research Center at the Stanford University Genome Technology Center and an active participant in several national clinician networks that focus on ME/CFS, Mast Cell Activation Syndrome, and Autoimmune Disease.    

Dr. Kaufman is currently a working member of the U.S. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Clinical Coalition and part of the Guideline Committee. He helped write the consensus recommendations that has been published in the Mayo Clinic proceedings.

Ilene Ruhoy, MD

Dr. Ilene Ruhoy is a board-certified neurologist and an environmental toxicologist who specializes in chronic and complex illness.  She graduated from the University of Pittsburgh School of Medicine and completed her residency in neurology at the University of Washington where she also did additional fellowship training in neuromuscular disorders. She earned a PhD in Environmental Toxicology at the University of Nevada, working directly with the Environmental Protection Agency (EPA) on her dissertation topic of 'Pharmaceutical Residues in the Water.' Dr. Ruhoy also completed a fellowship in Integrative Medicine with Dr. Andrew Weil at the University of Arizona. 


Dr. Ruhoy's interests include connective tissues disorders such as EDS, autoimmune neurological disorders, neuromuscular disorders, intracranial vascular and pressure disorders, infection associated neurological conditions such as Long Covid, MECFS, and PANS/PANDAS, traumatic and inflammatory brain injury, mitochondrial disease, neurodegeneration, and exposure illness. 


In addition to her private practice in Seattle, WA, Dr. Ruhoy also serves as the Medical Director of the Chiari EDS Center at Mount Sinai South and has become a well sought after speaker on the role of connective tissue in neurological disease. She is currently a co-editor of the special issue of Neurology and Connective Tissue for Frontiers in Neurology. Dr. Ruhoy has also been a co-editor of Integrative Neurology published by Oxford Press and a co-editor of Preventive Neurology, of the Seminars in Neurology series. She is the Chair of the Neurology Working Committee for the EDS Society and is also a part of the Neurology Working Group for the national apheresis organization, AFSA. She has been part of many chronic illness committees and serves on the boards of several organizations that focus on patients with EDS and chronic neurological disease.  


Dr. Ruhoy is currently accepting new patients by MD/DO referral only.

Our Doctors

Our Clinic 


2500 Hospital Dr, Suite 4b

Mountain View, CA 94040

2206 Queen Anne Ave N, Suite 303
Seattle, WA 98109

Phone Number

(650) 447-3001


Business Hours

Monday to Friday

9 AM to 5 PM

Saturday and Sunday



Our Policies


Our goal at the Center for Complex Diseases is to provide you with the highest level of personalized care.  We are committed to helping you achieve optimum health. We understand that these disorders that cause chronic illness include a large number of symptoms, which may be severe and disabling. However, precisely because they are chronic illnesses with complex symptoms, it will take time, testing, patience and trials of many different treatment approaches to achieve improvement. We will do our best to help you accomplish your healthcare and wellness goals.

Please note that our practice is designed to provide chronic disease management, not acute care. If you have a new symptom(s), you should be evaluated by your primary care provider, in order to be sure that you do not have a new, unrelated problem. If you have worsening and/or severe acute symptoms, you should call 911 or be evaluated by the nearest urgent care facility or emergency department.


Center for Complex Diseases does not contract with any insurance companies. We deeply regret the negative impact this will have on patients. The current health care model in the United States simply does not provide for appropriate reimbursement given the amount of time and level of care that we provide for our patients with chronic complex illnesses. Under the current insurance based health care system, most internal medicine doctors schedule 45-60 minutes for a new patient and see 4 or more follow up patients an hour. Conversely, at CCD, a new patient visit is generally scheduled as two hours of face-to-face time, plus extensive additional time devoted to review of records prior to the visit and preparation of records and test orders after the visit. Most new patient visits, therefore, involve about 3.5-4 hours of physician time. We will provide you with a billing summary that you may submit to your insurance company for possible reimbursement. At least partial reimbursement may be possible if you have out-of-network coverage. 

Dr. Kaufman and Dr. Chheda are not enrolled in the Medicare program. If you are a Medicare Part B beneficiary and wish to become a patient of the Center for Complex Diseases, you are required, according to the rules set forth by Medicare, to accept the terms and conditions set forth in a private contract between you and the Center for Complex Diseases. This private contract outlines that no Medicare payment will be made to you or to the Center for Complex Diseases for the services provided by our physicians, even if such services are covered by Medicare. Under this private contract, you acknowledge that you accept full responsibility for all charges for services provided by the Center for Complex Diseases, and that payment is due in full at the time care is provided. Laboratory, imaging and other testing as well as medications ordered by us are usually covered by most insurance companies including Medicare, but it is your responsibility to verify whether this is the case for your specific plan.

ALL CONSULTATION appointments as well as ALL EMAIL CORRESPONDENCE are subject to our current fees. Please ask the front desk for a list of current fees. 

Our Fee schedule incorporates the actual time you spend with your physician, the time your physician spends reviewing your medical records and labs, and the time post-visit preparing chart notes, ordering tests, and writing treatment protocols. For example, on average, a routine follow up consultation includes at least 30-45 minutes spent with your physician and at least 15-45 additional minutes charting, ordering new tests, researching, and preparing protocol updates. 

Acute Telephone Consultations, deemed necessary by the medical practitioner because of a sudden new problem or need for medication change, will be billed in 15 minute increments. "Consultations" refer to the total time spent, including chart review and conversation, preparation of chart notes, additional test orders, and prescriptions (For example, a 25 minute conversation plus 15 minutes post conversation on notes etc. will incur a 45 minute charge.) 

New Patient Appointment and Your First Follow up.

Most of the first visit will be to gather information about your case. This

includes a detailed comprehensive visit with your doctor at CCD to review, in great depth, your history, symptoms, prior records, and a physical examination.

You are encouraged to organize and provide the most pertinent medical records in order to improve the efficiency and effectiveness of the record review process. For example, please provide key laboratory tests (both positive and negative), pertinent radiological and other tests, and pertinent consultation notes from other clinicians. The patient who provides a random stack of a few hundred pages with multiple copies of the same results or a CD with years of provider follow-up notes unrelated to your current issues may result in a higher consultation fee and less valuable visit than the patient who sends ahead 75 pages of pertinent results and brings a binder to the initial consultation with other results that may or may not be needed, organized by Labs, Radiology studies, Other studies, and Consultations.

Organizing your thoughts ahead of time to allow a focused review of your story is also very helpful and important. Generally, providing a 1 to 3 page chronology is the most informative starting point. For example, summarizing in 10-15 minutes all of the medical issues you may have faced in your childhood years is more helpful than spending 15 minutes detailing one experience that happened when you were 5 years old.

Please include a medication and supplement list that is current. It is also helpful to note medications that you may have taken in the past (including approximate start and stop dates) but that you are currently not taking, and if there were adverse reactions to any medications.

First follow up visit 

The time varies depending on the complexity of your case and how much education we were able to cover in the first visit. This first follow up usually takes about 60-90 minutes face to face with the patient.

Review and analysis (in the context of your personal clinical situation) of laboratory results and other studies ordered at the initial consultation will be done during this visit, as well as a discussion of any symptom changes based on treatments that may have been initiated at the initial visit. This is followed by a discussion of diagnoses and additional treatment recommendations, as well as disease education. Additional tests are often ordered based on the results from the initial visit as well as any changes that may have occurred, and to monitor effects of treatment.

Follow up visits - continuity of care

Given the complexity of the illness we expect patients to have follow up visits at a minimum of every 2-4 months. 

Cancellation Policy

Due to long appointment times, no-shows and late cancellations are particularly problematic and we ask for your help in avoiding missed appointments. 

For new patient initial consultation any no-show or cancellation less than 15 business days before the scheduled appointment time will result in the loss of the deposit.

For follow-up visits, there is a 5 business day  cancellation policy for all consultations. If you need to cancel an appointment, you must do so PRIOR to your scheduled appointment, in the appropriate time frame, as stated above, or you will be charged for the scheduled visit. For example, if calling to cancel an appointment that falls on a Monday, please call to cancel the appointment the Wednesday prior to your appointment. Any no-show or cancellation less than 5 business days of the scheduled appointment time will be charged the full visit amount. For visits cancelled after the cancellation window, we will attempt to reschedule another patient into your time slot. If we are able to successfully reschedule another patient, then you will not be charged. This is not always possible with such short notice. If the reason for cancellation is your inability to get to the clinic, your visit can be conducted by Telephone.

Transfer of care 

Center for complex disease is a single medical practice with two physicians. A patient cannot transfer care to other doctors in the practice. There are no exceptions to this policy.

Prior-Authorizations I Pre-Authorizations I Appeals I Letters of Medical Necessity 
There are no FDA-approved treatments for ME/CFS (SEID), dysautonomia, mast cell activation syndrome, and many other conditions that we treat. These conditions are poorly understood by insurance companies. As a result, insurance companies often request extensive and time-consuming documentation to consider approval of many of the treatments used for these conditions. The number of these requests for our patient population far exceeds that of most other practices and we must charge for this service. If your insurance company requires Center for Complex Diseases to obtain a "prior-authorization," a "letter of medical necessity," an “appeal,” or a “peer-to-peer” physician consultation for medications, radiology, procedures or other care, you will be charged a fee for this service. Prior Authorizations (PA) for medications will be processed using the electronic platform Cover My Meds. The fee for this is $50 per medication .  However, if your insurance company does not participate with Cover My Meds, does not accept the application via Cover My Meds, or requires further verbal (phone) information, we will not pursue this PA further by attempting telephonic contact with the company. These calls are enormously time consuming, with long wait times, frequent disconnections, endless phone trees, and mostly unsuccessful once a human being is actually reached.  There is no guarantee that your insurance company will decide in our favor as a result of our actions, but we will make every effort to get the care you need approved. 

Below is a fee schedule for the above services. These are starting costs for these services. The cost will be determined based on the complexity of the service, and office staff and physician time spent on these services. This does not include the charge for IV medications as this process is more complicated and will be discussed with you if it is pertinent to your medical care. There is no guarantee that your insurance company will grant an approval based on any of our efforts on your behalf. 

All pre-authorization" or "prior-authorization" for oral medications - $ 50 and up

All pre-authorizations or prior-authorizations for IV medications- $500 and up

All pre-authorization" or "prior-authorization" for Imaging $150 and up 

Physician phone calls to insurance medical staff (peer to peer phone calls) $250 and up

Please note - We cannot order and process imaging requests from other doctors

Laboratory and Other Procedures

We do NOT do “pre-authorization” or "prior-authorization" for any LABS. We do not guarantee that recommended laboratory studies or procedures will be reimbursed by your insurance company. It is your responsibility to ensure that laboratory tests, procedures or other tests ordered by Center for Complex Diseases are covered by your insurance policy prior to these studies being completed. If your insurance company requires a different or additional diagnosis codes, we are happy to change the submitted codes if appropriate. If you request more extensive staff involvement to try to get tests covered after the fact, you will be billed starting at $50.00. If provider time is requested for this reason, it will be billed at the provider rate.

Laboratory and Other Procedures for certain HMO  insurances ( eg Kaiser)  and Uninsured Patients

Given that there is no coverage for Laboratory and other Procedures, for new patients the cost can be in the range of $5000 and upwards. 


Prescription Refills
Prescriptions are best ordered during your scheduled office visit. We will order enough refills to last until your next recommended follow-up visit. The frequency of recommended follow-up visits depends on the stability of your condition and the medication(s) prescribed. No medications will be prescribed for more than 6 months. If you require a refill prior to your next office visit, you MUST request this at least one week in advance. 

Prescriptions initiated by another provider should be refilled by that provider unless Dr. Chheda/ Kaufman agree to take over the prescription. It is your responsibility to be sure you do not run out of your medication by scheduling office visits at appropriate intervals.

Portal Email messages 

Portal and other messages are intended for non-urgent, NON- COMPLEX and logistical matters.

If you have an urgent or emergent matter, please go to the nearest emergency department or urgent care. 

If you have a COMPLEX situation or question, please schedule a telephone or in-person appointment. Given the high level of illness severity in our patient population, we receive a large number of portal messages that far exceeds that seen in other practices and we must charge for this service if provider time is required. We anticipate that we will have 2 to 3 simple SHORT communications between appointments through the portal. There will be no charge for this if it falls within these guidelines. 

Diagnoses will NOT be made over the portal and new medications will NOT be started over the portal. If you send a lengthy update to the physician, there may be a charge for reading the message even if no response is needed. It is important to understand that patient emails very frequently (and appropriately) require a chart review before providing a response.

We do attempt to address portal messages as soon as possible, but given our small office, there may be times when we cannot get to your message for 72 hours or even longer, especially over weekends, holidays, or if there is a staff or physician absence. 

In some situations, we may utilize the portal messaging to manage dosing adjustments, additional testing, etc based on symptom response, side effects, etc. This process often takes significant physician time and will be charged accordingly.

Portal messages are NOT a substitute for appointments

No new medications will be prescribed outside of a visit except in exceptional situations or by pre arrangement at the time of a visit.

Questions/concerns/updates that need to be addressed by a physician will be billed at the current provider rate in 10 minute increments of provider time required to address your question or concern.


Test Results

Routine monitoring labs (CBC and CMP) for patients on infusion therapy or certain oral medications do not require an appointment if they are normal. If there are important or urgent laboratory abnormalities, however, a follow up appointment or brief telephone appointment must be scheduled, so that these results and their potential implications may be properly addressed including any changes in treatment. Non urgent labs and other diagnostic test results will be discussed at your scheduled follow-up appointment. If there is a test result that you are worried about and do not want to wait until your scheduled follow up appointment, you may schedule a short follow up appointment or call. Please note that some specialty tests can take as long as 6 weeks to be finalized.


Forms that can be completed by staff and signed by a provider will be completed at a minimal charge, e.g. handicap parking or school excuse forms. 

Forms that require physician time to complete will be charged at the clinician rate, e.g. disability forms, letters for travel, etc. 


If you need a letter drafted for any reason, you will be charged the provider rate based on the amount of provider time required to draft the letter. We use HIPAA compliant, encrypted email; however, if your email or where it is requested to be sent to is not encrypted, we cannot guarantee the security of the personal information that may be contained in the letter.


Medical Records Copy

Your Center for Complex Disease records are available on our patient portal by request. There is no charge for this. Medical records will be faxed via the EMR to your other providers on your request. There is a reasonable, cost-based fee for this service.  Please ask the front desk for a list of current fees. 


We cannot guarantee your health will improve as a result of our care. Because of the chronic complex illnesses our patients present with, we pursue an extensive diagnostic work up and strive to find treatments, both conventional and novel, that may lead to an improvement in quality of life. This is always our goal, but, as with everything in medicine (and life), nothing is 100% successful.

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