
Dr. Rex L. Mahnensmith, M.D.
Adolescent Specialist | Adolescent Medicine
832 Queen Street Southington Connecticut, 06489About
I am continuing to serve as a Practicing Internal Medicine Physician. The central focus of my care is the individual. I aim to listen, to understand, to sort out the active concerns of each individual and to address each. I will actively address any expressed and discovered concern, and will make referrals as needed. My care aims to be proactive and preventative - to provide screening and advice and counsel regarding health maintenance and wellness achievement. My care also will address acute illnesses and established chronic ailments and health concerns. And my care shall embrace and address complex and high risk burdens of illness. My Calling as Physician is to provide -- and deliver -- personalized care that carefully considers the individual's burden of illnesses, the health changes that she or he is experiencing, and then aiming to carefully provide effective remediation. I am to actively consider special concerns and fears and needs as they unfold. It is with humility that I serve in this chapter of my Vocation -- truly taking time to listen, to hear, to respond, to show empathy, and to make deeply considered and personalized clinical decisions. I pledge to serve carefully and tenderly, expressing value, concerns, hopes, counsel and education to individuals as I deliver particulars of clinical care.
I am blessed with good health myself. I have served for over 30 years as Teaching Physician in three University Medical Centers. My teaching harmonized well with my clinical service and patient care during these years. I served both in outpatient clinics and on hospital units, supervising students and residents in concert with direct care responsibilities. These years were fulfilling. I aimed to deliver best care to patients - and I aimed to model best care as well. I regularly talked to students and residents about the special "Calling" of a physician - the privilege, the responsibilities, the duties, and the opportunities to make a difference to individuals and families. I received several teaching awards over these years, and I received several "Model Physician Awards" as well. These years were filled with gratification and positive relationships. I thoroughly enjoyed clinical teaching and I poured my heart and mind and soul into each moment. I served as Associate and then Full Professor of Medicine at Yale Medical School from 1992 to 2014. During these years, I also served as "Clinical Advisor" to the Chairman of Medicine and I serve as "Advisor" to National Medicare Dialysis Oversight Committee. I also served as Medical Director of Dialysis at Yale from 1994 to 2014 and as Regional Medical Director of Dialysis for two National Dialysis Corporations from 2001 through 2006. In these Medical Director of Dialysis Roles, I was responsible for Quality Assurance and Dialysis Safety in local dialysis clinics in New Haven, CT and I also served as a Regional Educator regarding Quality Assurance for hundreds of dialysis clinic leaders across 30 states in Eastern U.S. In this capacity, I lead the development of several Clinical Pathways which were implemented within the operations of these dialysis clinics and which resulted in high quality care and excellent clinical outcomes.
In 2014, I retired from Yale University Professorship as Tenured Professor Emeritus - - and I transitioned to serving individuals and families in Skilled Nursing Facilities, providing General Medical care to many persons with various chronic illnesses. In this context, I had the capacity to really take time with individuals --- to sit and listen, to hear and to understand their concerns, and to deliver personalized care like never before. In this, I realized my Deepest Calling as a Physician -- primary, holistic care of individuals in their own special contexts, delving deeply into their unique social contexts, knowing deeply their burdens of chronic illnesses, responding promptly to any acute health change that they were experiencing, and addressing their various problems and fears. I took this step in my career journey so that my wife and I could live in a small town in northern Connecticut where our daughter and our grandchildren lived, so that we could help with their care and familly needs. This step was very positive.
In 2015, I transitioned to a Community Health Clinic setting, where I served as Primary Care Physician addressing multiple individuals' needs and concerns. It is with humility that I served in this chapter of my "Vocation" -- truly taking time to listen, to hear, to speak, to show empathy, and to make deeply considered, and personalized clinical decisions - and aiming to catalyze positive change in each person's health and sense of well-being. I served as Chief Medical Officer for the CHC into 2017, then transitioned to a Private Practice Group - DOCS of Connecticut.
Through all, I have truly hoped to be a light that shines, just enough to give warmth and illumination and to be a kindling source for others' whose light is dimming or flickering. I have hoped and continue to hope to confer a true sense of genuine caring to each person that I serve - - caring for the person but also caring about the person -- recognizing and serving within their specific social context.
Serving in this way, serving carefully as a caring physician, has been and is my Calling. I intend to serve thusly as long as God wills and by His Strength and Wisdom.
Professional Honors and Recognition:
Apr 1972 Phi Beta Kappa, Sigma Xi, Omicron Delta Kappa, Denison University
Sep 1972 Teaching Fellow, Denison University
Jun 1976 Lange Award: "Clinical Excellence". Yale
May 1977 Alpha Omega Alpha, Yale
Jun 1977 Berniker Award: "Most exemplary of The Oath of Hippocrates and Maimonides Prayer" Yale
Jun 1979 Kushlan Award: "For clinical excellence and contributing the most to patient care" Yale
Jul 1983 National Kidney Foundation, Research Fellowship Award, Yale
Jun 1985 Duke University "Special Recognition for Teaching"
Jun 1988 "Teacher of the Year" Brown University
Jun 1988 "Model Physician Award" Brown University
Jun 1989 "Senior Class Outstanding Teacher Award" Brown University
Jun 1989 "Teacher of the Year", Miriam Hospital, Brown University
Jun 1990 "Model Physician Award", Miriam Hospital, Brown University
Jun 1990 "1990 Senior Citation: Outstanding Physician and Teacher" Brown University
Jun 1991 "Senior Class Outstanding Teacher Award", Brown University
Jun 1991 "Model Physician Award", Miriam Hospital, Brown University
Jun 1992 "Teacher of the Year", Miriam Hospital, Brown University
Jun 1993 "Teacher of the Year", Yale Internal Medicine
Jun 1993 "Howard M. Spiro Teaching Award", Yale University Affiliated Hospitals
Sep 1997 "Didactic Professor Award", Yale University Physician Associate Program
Sep 2009 "Didactic Professor Award", Yale University Physician Associate Program
Jun 2011 "Emergency Medicine Resident Appreciation Award", Yale Emergency Medicine
Oct 2012 "DaVita Shining Star Award" -- for service excellence in their dialysis clinics
Sep 2013 "Branford-DaVita Service Appreciation Award"
Dr. Rex L. Mahnensmith, M.D.'s Videos
Education and Training
MD at Yale School of Medicine
Yale New Haven Hospital Internal Medicine Residency 1980
Yale University Fellowship Nephrology Metabolism 1984
Board Certification
American Board of Internal Medicine
Nephrology (Internal Medicine)
Provider Details

Dr. Rex L. Mahnensmith, M.D.'s Expert Contributions
Five Life Habits That Make A Difference For Health and Survival
Habitual tobacco use, irregular and insufficient exercise, regular intake of alcoholic beverages above a minimal amount, being overweight for one's height, and sleeping less...
Goals for the Care of Diabetes Mellitus
Diabetes Mellitus is defined by elevated blood glucose concentrations. Blood glucose concentrations should reside below 100 mg/dL during fasting time periods. Biologic Normal Blood Glucose is 70-99 mg/dL when "fasting.""Fasting Time Periods" refer to any time frame beyond 2 hours after eating,...
Knowing All About Sugar Essential for Life but Potentially Unhealthy Part 1 of the Diabetic Story
Sugar is the familiar and common name for sucrose, a naturally occurring substance in nature that is formed in plants from the combination of water absorbed from soil and carbon dioxide absorbed from air. Yes, sugar is composed simply of water and carbon dioxide. Sucrose is a complex sugar composed...
Knowing All About Sugar: Blood Vessel and Tissue Injuries Develop When Blood Glucose Concentrations Circulate Above Normal Even For A Short Time: Part 2 of the Diabetic Story
Glucose is the essential energy molecule that our body's tissues utilize. Glucose exists in fruits and vegetables and grains, either as a simple sugar or as a structural component of plant starches and complex fiber carbohydrates. All carbohydrates must be broken down to glucose and fructose in our...
Knowing All About Sugar: Essential for Life but Potentially Unhealthy: Part 1 of the Diabetic Story
Sugar is the familiar and common name for sucrose, a naturally occurring substance in nature that is formed in plants from the combination of water absorbed from soil and carbon dioxide absorbed from the air. Yes, sugar is composed simply of water and carbon dioxide. Sucrose is a complex sugar...
Vitamin K2: A Little Known Vitamin That We Now Know Reverses and Prevents Artery Calcification and Promotes Bone Matrix Calcification
A “vitamin” is a nutrient essential for life. We are well-acquainted with most vitamins, such as vitamin A, the B-vitamins, and vitamins C, D, and E. Each has a well-known and essential role in support of vital tissue functions, and each must be ingested from particular food sources, with the...
Why Delve Deeply into Our Daily Nutrition? Because we Become what we Eat!
Our daily food and beverage intake may be a matter of deep thought and careful selection. Or, our daily food and beverage intake may be a matter simply of convenience, routine, habit, and taste. What has become clear from many years of impressive scientific research is that daily nutrient flows...
Bilateral adrenal adenomatous hyperplasia?
Hi, The bilateral adrenal enlargement can be a result of extra stimulation from pituitary ACTH. And this may indicate hormone imbalance. So, blood testing for ACTH and cortisol is important. If you have required corticosteroid therapy in prior months, then your own production goes down. READ MORE
Medication side effects?
Sudden cessation of mirtazepine will bring on nausea and cramps and lightheaded feelings. Promethazine is generally well tolerated as an anti-nausea medicine, but can have side effects. READ MORE
Burning sensation in groin area. Not STDs or fungal infection?
You are receiving very good care. The symptoms are consistent with neuralgia. READ MORE
Stomach or fibroids?
Okay. The fibroids are located in your lowest abdominal spaces. They will not cause pressure on your stomach or upper small intestine tissues. Your stomach symptoms are separate in basic causation. Early satiety reflects delayed gastric emptying most commonly. Reflux happens with delayed gastric emptying also and with hiatal hernia and spasms. Special imaging studies are warranted if esophagus and stomach and small intestine READ MORE
Should I go to urgent care for abdominal pain?
Yes. Evaluation is essential. READ MORE
Breathlessness?
Hello, These experiences are not usual. Considerations for an office exam include: exercise induced asthma, bronchitis, a lung ailment that is reducing oxygen exchange, a heart condition, or a circulatory condition. Rex READ MORE
Recurring cellulitis and sepsis?
Greetings, Vitiligo is typically not a source of infection. Vitiligo though may be abraded by itching and then could be a source of skin bacteria colonization. Analyze your skin areas; look for clogged skin pores or abrasions or itch sores. Consider hair follicles that may harbor bacteria. Be wary of scratching. Rex READ MORE
I am stopping everything cold turkey today, will I be ok?
I believe it would be a bit wiser to taper supplement intake over one week. Reduce by 20 percent each day. READ MORE
Always hungry?
One possibility is prediabetes or early diabetes with slow uptake of glucose. Thus your tissues are underfed while glucose circulates in your blood. Testing is important for this. A second possibility is leaky bowel. If your colon is sluggish, then lectins get absorbed. Lectins interfere with natural appetite regulators. This requires colon cleansing and diet changes and then regular full bowel evacuation daily plus healthy prebiotic and probiotic supplements. READ MORE
Test result meaning?
First, the alkaline pH most commonly arises from an active bacterial urinary infection. The bacteria change the urine pH to alkaline. In a rare circumstance, a person can show an alkaline urine from extreme consumption of alkaline foods such as greens. This is very rare. Your urine is infected. Bactrim is prudent. Urobilinogen is ordinary in small amounts. Urobilinogen comes from ordinary metabolism of bilirubin from the liver and is excreted as a waste. Normally, most uribilunogen comes through the liver into bile ducts and then is dumped into the intestine and is excreted with bowel movements. An increase in urine urobilinogen is of concern: liver dysfunction can disturb normal passage of urobilinogen through bile ducts, such as bile duct blockage or an inflamed liver. Or, if a hemolytic anemia is active, then more bilirubin is made from the released hemoglobin. READ MORE
Autoimmune diseases and Insomnia?
Hello, Most likely, the fatigue relates to inflammation activity in your body from RA. And, your energy cycles likely relate to medications you are taking. Rex READ MORE
I am afraid I might have penile cancer?
Hi, This sore is most likely urethritis, not a cancer. It is essential for you to have a urine test and a blood test for infection analysis. These tests are ordinary and can be accomplished at an Urgent Care clinic. Antibiotic is curative. Cleansing is essential too. READ MORE
Do you think smart watches with heart rate are accurate?
As you have noted, the pulse watch can pick up other movements and vibration that are not pulsation. READ MORE
Iron supplement constipation?
Iron tablets are likely to alter bowel movements, yes. It is well known. Yes. To reduce constipation with iron, take each tablet with additional vitamin C. A 500 mg tablet with the iron tablet will enhance the intestinal absorption of iron. Also, drink a minimum of 6-8 ounces of fruit juice with the iron tablet and vitamin C. This enhances absorption and disperses the iron compound. And repeat the glass of fruit juice twice more. And eat more food fiber such as an apple, a pear, a peach, or high-fiber oatmeal each day is important. And yes, a daily regular capsule of Senna plus Colace is important and essential. READ MORE
60 year old woman with chronic diarrhea no other symptoms?
So sorry for your persistent diarrhea. The normal colonoscopy is very valuable information. Other essential testing: 1). Food allergies blood testing. Is a routine lab draw. Requires an order. 2). Celiac disease panel. Is also a routine lab draw. 3). Eliminate dairy foods for four weeks as a trial. 4). Eliminate gluten foods also for four weeks. 5). Stool test for Clostridium diffocele. 6). Stool test for giardiasis. 7). Reduce animal fat intake. 8). Take probiotic daily. 9). Minimal caffeine. 10). More fiber in form of leafy greens, apples, bananas. If you have a chronic condition such as diabetes, then review with your diabetes specialist. READ MORE
Is it normal to feel tired after a CT scan?
Not usual. Not “normal.“ The CT scan is a computerized X-ray. The CT scan may be enhanced by the administration of intravenous radiocontrast dye. The dye circulates through blood vessels and then is excreted through the kidneys. This dye has a diuretic effect and can lead to dehydration. So, if one received the radio contrast dye then dehydration and fatigue may follow. READ MORE
Is abdominal pain after COVID infection normal?
Coronavirus infection is largely respiratory. It can reside in nostrils and pharynx or it can cross through respiratory tissues. Our immune system will respond with inflammatory molecules to eradicate infection. Inflammatory molecules can incite muscle aches and gastrointestinal reactions that may include cramping or vomiting. Heavy mucus that is swallowed will also incite similar gastrointestinal symptoms. Long-lasting pain should be evaluated. READ MORE
Should those test results be considered valid?
No. Tests were done in context of Ativan adverse reaction. READ MORE
Pain in lower left side of stomach?
Your ailment requires exam and testing: physical palpitation, ultrasound and CT scanning (or MRI), blood and urinalysis. The region of your discomfort includes upper colon, spleen, outside left wall of the stomach. Persistent ache and pain can indicate inflammatory reaction to infection or diverticulitis or polyp or neoplasm. READ MORE
Can you get lung inflammation from covid?
Yes!! And lung inflammation is the mayor concern and the major illness that arises. Coronavirus is unique in its way of sticking to respiratory membranes. The virus sticks and holds and enters. Our body’s response to this is a surge of white blood cells and lymph cells to consume viruses, and plasma follows. Lungs become wet and heavy with these inflammatory materials, and this impairs respirations. READ MORE
Expert Publications
Data provided by the National Library of Medicine- Pericarditis associated with renal failure: evolution and management.
- Hypercalcemia, hypernatremia, and reversible renal insufficiency.
- A quality improvement model for optimizing care of the diabetic end-stage renal
- Advances in nephrology: a selected review of progress in care of the patient with renal failure.
- Urgent-start peritoneal dialysis: what are the problems and their solutions?
- Novel treatments of autosomal dominant polycystic kidney disease.
- Diabetic nephropathy: a comprehensive approach.
- A middle-aged woman with back and flank pain.
- Angiotensin-converting enzyme inhibitor therapy in chronic hemodialysis patients:
- Trimethoprim-sulfamethoxazole: hyperkalemia is an important complication regardless of dose.
- Dysuria in an elderly man with cardiomyopathy.
- Bone marrow transplant nephropathy: a case report and review of the literature.
- Hyperkalemia in the elderly: drugs exacerbate impaired potassium homeostasis.
- Images in clinical medicine. Malignant hypertension.
Areas of expertise and specialization
Faculty Titles & Positions
- Professor, Duke University, Brown University, Yale University -
Awards
- Teacher of the Year.Brown Univ.1988, '89, '90, '91, '92
- Outstanding Teacher. Yale Univ. 1993, '97, 2009, 2011
- Model Physician. Miriam Hosp. 1988, '90, '91
- Dialysis Medical Director Excellence. 2011, 2013
- Outstanding Teacher. Duke U. 1985
- Leading Physicians of the World 2016 International Association of Health Care Practitioners
- Berniker Award - Most Exemplary of Prayer of Maimonides 1977 Yale U
- Kushlan Award - Best Bedside Manner and Care 1978 Yale NH Hospital
- Chief Resident 1980 Yale U Dept of Medicine
- Who's Who Honorary 2017 Continental Who's Who
- Marquis Who's Who 2022 Marquis Who's Who
- Patient Preferred Award 2021 Patient Preferred Physicians
Professional Memberships
- American Medical Association
- American Society of Nephrology
Charities and Philanthropic Endeavors
- Compassion International Aid Society
- Send International Missions
- CRU Campus Missions
- Ligonier Ministries
- HAVEN
- ASPCA
- Christ Community Church in Collinsville
- Samaritans' Purse
- World Vision
Internships
- Yale New Haven Hospital Internal Medicine
Fellowships
- Yale University Nephology
Professional Society Memberships
- AMA and ASN
Favorite professional publications
- JAMA
Areas of research
Nutritional Care of the Person with Chronic Kidney Disease
Optimizing Diabetic Control
Nutritional Care of Polycystic Kidney Condition.
Pharmacologic Care of Polycystic Kidney Condition.
Impact of Clinical Pathways on Promoting Quality Improvement in Clinic Settings
Dr. Rex L. Mahnensmith, M.D.'s Practice location
DOCS Medical Group
832 Queen Street -Southington, Connecticut 06489Get Direction
DOCS Medical Group
279 Chase Avenue -Waterbury, Connecticut 06704Get Direction
Dr. Rex L. Mahnensmith, M.D.'s reviews
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Nearby Providers
- Dr. Arthur T. Blumer M.D.340 Main St Southington Connecticut 06489
- Dr. Husam Bahgat Shitia M.D.430 Highland Ave Cheshire CT 06410
- Dr. Ishrat Quadri MD1162 New Britain Ave West Hartford CT 06110
- Dr. Kristin Mcgregor MD57 JOLLEY DR BLOOMFIELD CT 06002
- Mrs. Marie helene Pouliot MD1062 Barnes Road Wallingford CT 06492
- Dr. Robert Raphael Toscano M.D.33 Canal St Weatogue CT 06089
Nearest Hospitals
BRISTOL HOSPITALl
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