Karthik Subbu, MD

4.9

716 ratings Read Reviews

Northwestern Medicine Regional Medical Group

Primary Specialty

Endocrinology

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Practice Focus Areas

This medical professional has a particular interest or expertise in:

Adrenal Disorders
Diabetes
Parathyroid Disease
Pituitary Disorders
Thyroid Disease

Education

Medical Education:: MD, Eastern Virginia Medical School - 2018
Residency:: Indiana University School of Medicine - 2021
Fellowships:: University of North Carolina Hospitals - 2023

Languages Spoken

Tamil

Board Certifications

American Board of Internal Medicine - Internal Medicine (Certified)
American Board of Internal Medicine/Endocrinology, Diabetes and Metabolism - Endocrinology, Diabetes & Metabolism (Certified)

Practice Groups and Affiliations

Medical Group:: Northwestern Medicine Regional Medical Group
Alignment Category:: Northwestern Medicine Physician Network
On Medical Staff At:: Delnor Hospital

Ratings and Reviews

At Northwestern Medicine, our patient’s feedback is important to us. While different care providers have their own unique strengths, we strive to be as transparent as possible with our quality of care.

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Overall Rating

4.9

4.9

716 Ratings

Reviews from Patients

100 Most Recent Reviews

Reviews from Patients

100 Most Recent Reviews

February 25, 2026

5.0

He always listens to the needs that I have with my diabetes has a great plan moving forward and is always if I call he always responds quickly would always Recommend

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February 24, 2026

5.0

Very personable. Incredibly kind. Easy to speak to

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February 24, 2026

5.0

Very detailed and addressed all my concerns

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February 24, 2026

5.0

Thoughtful, inquisitive and knowledgeable. Great guy!

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February 22, 2026

5.0

He's great!

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February 20, 2026

5.0

Very knowledgeable, very good communicator, made appointment easy

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February 20, 2026

5.0

He is knowledgeable and he cares about his patients as human beings. He's compassionate and committed .

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February 20, 2026

5.0

Listens and is caring. He makes you feel relaxed and comfortable .

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February 19, 2026

5.0

I want other diabetics to feel secure about the disease and how to take care of oneself.

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February 13, 2026

5.0

Fantastic bed side manor and very helpful with his advice.

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February 12, 2026

5.0

Dr Subbu is an incredible doctor very knowledgeable and empathetic takes the time to listen and understand and is incredibly helpful goes above and beyond in his care. I have been too many endocrinologist specialists, and by far he has been the best I've ever had.

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February 11, 2026

5.0

I would highly (10) recommend Dr. Subbu for healthcare because of his presence, interest, and knowledge throughout the visit and follow-up.

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February 11, 2026

5.0

All the above. An excellent physician! Couldn't wish for more!

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February 03, 2026

5.0

He's wonderful doctor He answered all my questions Thank you

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January 21, 2026

5.0

He is detailed in taking notes and following up from previous appointments. Also recommends any needed care for diabetes treatment

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January 19, 2026

5.0

Since I was a new patient, he was very thorough in looking over my history. He met my current needs & gave help!!

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January 14, 2026

5.0

They are very concerned about my health

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January 14, 2026

5.0

Dr Subbu is very friendly and takes time answering any questions posed.

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January 14, 2026

5.0

He's good and so understanding. Explains everything and never in a hurry

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January 08, 2026

5.0

He listens to his patients!

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January 07, 2026

5.0

caring, personable, knowledgeable

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January 05, 2026

5.0

He is very knowledgeable and also very friendly.

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January 02, 2026

5.0

Great service

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December 31, 2025

5.0

Very nice and a strong interactive manner.

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December 30, 2025

5.0

Dr. Subbu does his best to help others improve their health.

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December 26, 2025

5.0

He explains the symptoms of your problems and how to correct them.

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December 18, 2025

5.0

Very detailed in explanation of results and process forward.

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December 18, 2025

5.0

He explains everything even when I kept asking the same questions he was great definitely will keep him as my doctor understanding very knowledgeable previous I have diabetes for 20+ years and have never had such great experience from doctor and staff not to mention the receptionists who quickly and efficiently took care of my needs

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December 17, 2025

5.0

Very compassionate and explains medical conditions in easy to understand terms

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December 16, 2025

5.0

I feel that he is a very good Dr and left there feeling that he listened to me and gave me great advice for my future

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December 14, 2025

5.0

He listens before speaking.

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December 13, 2025

5.0

Extremely knowledgeable. He answers all questions with a caring attitude

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December 12, 2025

5.0

Same as above-I'm new to Endocrinology, but the first two visits have gone well.

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December 11, 2025

5.0

Very helpful and really seems to care about you

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December 03, 2025

5.0

Caring and knowledgeable Dr with a holistic approach

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December 03, 2025

5.0

Very helpful

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November 29, 2025

5.0

Dr. Subbu, is very efficient in his diagnosis and has a good bedside manner.

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November 23, 2025

5.0

Dr. Subbu listened to his patient medical history in full detail without rushing. He showed flexibility in next steps to take and honored patient's wants.

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November 21, 2025

5.0

He explained everything

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November 18, 2025

5.0

patient, kind, explains everything very well

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November 18, 2025

5.0

Very knowledgeable and focused on providing personal advice.

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November 10, 2025

5.0

Excellent care Listens and checks all needed care

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November 05, 2025

5.0

Dr. Subbu Is the kindest, most compassionate Dr. I've ever been to. Anytime you're with him he makes you feel like you're his only patient. He never rushes, always presents himself as calm and professional, and listens to absolutely everything you say in detail. He is brilliant and friendly and someone I trust with my life.

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November 04, 2025

5.0

Overall good person

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October 30, 2025

5.0

He took the time to go through my health history and to determine the best plan of care for the future

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October 29, 2025

5.0

Easy to talk to

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October 20, 2025

5.0

I am thrilled to have Dr. Subbu as my endocrinologist. He, and his whole team, are incredibly responsive to all my questions - (I'm a new patient post thyroid cancer surgery). They have been stellar!

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October 17, 2025

5.0

He listens and very thorough

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October 15, 2025

5.0

I like Dr. Sabbu. He's easy to talk to and explains everything I need to know to keep my diabetes as stable as possible.

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October 14, 2025

5.0

He is trustworthy!

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October 13, 2025

5.0

Dr. Subbu patiently explained everything until I understood.

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October 10, 2025

5.0

Very knowledgeable professional who listens and works with patients

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October 07, 2025

5.0

Doctor is very knowledgeable as well as articulate in explaining the information.

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October 01, 2025

5.0

Why he understands my needs

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September 30, 2025

5.0

Nice mannerisms and supportive!

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September 29, 2025

5.0

Did good

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September 26, 2025

5.0

Very helpful in helping me y i my thyroid

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September 26, 2025

5.0

Very friendly and takes the time to discuss your situation. Works to keep off medication if possible.

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September 26, 2025

5.0

He takes the time to listen.

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September 26, 2025

5.0

Very good doctor.

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September 25, 2025

5.0

I would highly recommend Dr Subbu. He explained everything to me that was easy for me to understand. He answered all my questions and did not rush through my appointment. I have already told my PCP that I would highly recommend him.

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September 08, 2025

5.0

Very thorough explanation of treatment and tests performed. I did not feel rushed. Additionally, he reviewed my test results quickly and provided needed directions.

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September 08, 2025

5.0

Very thorough, caring and willing to listen

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September 04, 2025

5.0

My Favorite Dr ever!

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September 03, 2025

5.0

The doctor listens patiently and is very kind and very professional in his field.

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August 14, 2025

5.0

He a good doctor

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August 13, 2025

5.0

Dr Subbu

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August 11, 2025

5.0

Married down to earth, I explained everything very thoroughly.I felt very comfortable with him

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August 08, 2025

5.0

Professional

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August 07, 2025

5.0

Dr Subbu is a fantastic doctor. He explains your prognosis and resolutions for a healthy outcome.

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August 07, 2025

5.0

Dr. Sabbu is very caring, kind and knowledgeable.

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August 04, 2025

5.0

He actually listen to his patients concerns.

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August 04, 2025

5.0

He is very thorough and professional

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August 02, 2025

5.0

Dr Subbu was very thorough and answered all my questions

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July 30, 2025

5.0

Very good doctor.

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July 25, 2025

5.0

Professional, knowledgeable, personable, trustworthy, efficient.

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July 24, 2025

5.0

He is awesome!! Takes time to solve problems. We love him

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July 20, 2025

5.0

Dr Subbu has always been very thorough and understands my condition. He always makes sure all my concerns are answered.

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July 18, 2025

5.0

Very caring and professional yet kind. So happy to have found him.

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July 18, 2025

5.0

He seems to care.

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July 18, 2025

5.0

Dr. Subbu is patient and answers questions about my concerns.

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July 17, 2025

5.0

He is knowledgeable and caring.

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July 16, 2025

5.0

He was awesome. Very helpful, very thorough

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July 15, 2025

5.0

He a good doctor.

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July 11, 2025

5.0

A very good experience. Doctor, lab, efficient.

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July 10, 2025

5.0

Good work

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July 09, 2025

5.0

It's beyond words.He inspires confidence.

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July 09, 2025

5.0

Dr Subbu is exceptional! He is very smart and always on top of things. He listens to my concerns and questions and takes the time to answer thoroughly, makes sure I understand all my options. All of the above, as well as friendly and personable. I feel well taken care of and thankful to have him as my doctor.

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July 02, 2025

5.0

Truly listens and offers practical advice. He's encouraging to me and includes me in my care decisions.

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June 27, 2025

5.0

He was highly recommended by two acquaintances, and he obviously really "knows his stuff"!

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June 25, 2025

5.0

He is very thorough. The kind of doctor people look for!

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June 25, 2025

5.0

He is very knowledgeable.

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June 24, 2025

5.0

Very Attentive and aware of patient needs

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June 24, 2025

5.0

He explains all your questions and suggests the right things for you.

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June 23, 2025

5.0

Already recommended him to my wife who was diagnosed with Type 2 Diabetes

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June 20, 2025

5.0

Very thorough.

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June 18, 2025

5.0

He assessed where I was with medications and was concerned with my weight loss. He removed and replaced a medication that will correct the problem.

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June 17, 2025

5.0

See above . He is an excellent doctor.

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June 14, 2025

5.0

Dr Subbu is very thorough. He explained all of the tests and results in an understandable way. Dr Subbu also explained action to be taken going forward.

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June 13, 2025

5.0

He is very friendly and professional and explains everything very well so that you fully understand.

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Disclosures

Karthik Subbu, MD reported no external professional relationships for calendar year 2024.

External Professional Relationships

Pharmaceutical, device, and biotechnology companies frequently collaborate with basic scientists and physicians within an academic medical center to help advance science and improve patient care. These relationships are important in achieving scientific breakthroughs and in establishing the effectiveness and safety of promising new therapies. In order to assure objectivity in clinical research and patient care, the Northwestern University Feinberg School of Medicine (Feinberg), Northwestern Memorial HealthCare, Children's Hospital of Chicago Medical Center, and the Shirley Ryan AbilityLab have adopted integrity policies that require research and clinical faculty (in full-time, part-time, and unpaid/voluntary categories) to report compensated and uncompensated external industry relationships. Patients are encouraged to discuss these disclosures with their physician as well as to inquire as to how these relationships are overseen by Feinberg. To learn more about our Disclosure and Professional Integrity Policy, and the conflict of interest policies of our joint affiliate survey partners, please go to our Office for Regulatory Affairs Policies page.

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