Obesity – Diagnosis, Symptoms, and Treatment

Medically Reviewed by Dr. Po-Chang Hsu, MD, MS

Medically reviewed by Dr. Po-Chang Hsu, MD, MS

Medical Professional

Updated - January 11, 2021

Dr. Po-Chang Hsu is a medical doctor from Tufts University in Boston, Massachusetts, interested in pediatrics and neonatology.

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What is Obesity?

Obesity is defined as a body mass index (BMI) ≥30 kg/m2.  This is generally seen in individuals who have a high body fat content.  Obesity is usually caused by genetic and environmental factors such as poor diet and lack of physical activity.  Certain medical conditions and medications can also contribute to obesity. Therefore, it is best to be informed to see what can help with weight loss.

Obesity is associated with numerous other comorbid conditions, including hypertension, elevated cholesterol, diabetes, heart disease, obstructive sleep apnea, pulmonary hypertension, gastrointestinal reflux, and various cancers.  It is also a leading cause of osteoarthritis and pain in the back, hip, and knee.

Due to this condition importance, patients must understand its causes, symptoms, and treatment.  By the end of this article, you will have the answers to these essential questions

  •         What causes Obesity?
  •         How common is Obesity?
  •         What are the symptoms and signs of Obesity?
  •         How is Obesity diagnosed?
  •         How is Obesity treated?

What Causes Obesity?

Genetic and environmental factors cause obesity.  It tends to run in families – it is also seen in individuals who consume diets high in carbohydrates and saturated fat.  Individuals who are obese are generally inactive and uncommonly perform an exercise.  Certain diseases are associated with obesity, including:

  •         Hypothyroidism
  •         Diabetes mellitus type II
  •         Cushing syndrome

Certain medications such as antidepressants, beta-blockers, antihistamines, and corticosteroids can also be associated with obesity – especially if used long term.

How Common is Obesity?

Obesity is exceedingly common in the United States and responsible for frequent primary care visits.  The most common causes include poor diet and lack of exercise.  In severe cases, the condition may require referral to a bariatric surgeon.

Greater than 2/3rds of American adults are trying to maintain or reduce their weight at any given time.  Only about 20% are dieting or performing a physical activity to reduce their weight.

In the United States, the prevalence of obesity in 2014 was approximately 30%.  There is a higher prevalence in the Midwest and South.  Rates of obesity appear to be stabilizing despite surges in the 1990s and early 2000s.

What are the Symptoms and Signs of Obesity?

Obesity is not responsible for any specific symptoms in and of itself – its symptoms typically occur as a result of its complications such as:

  •         Hypertension
  •         Elevated cholesterol
  •         Type II diabetes
  •         Heart disease – coronary artery disease, heart failure
  •         Obstructive sleep apnea
  •         Pulmonary hypertension
  •         Gastrointestinal reflux
  •         NASH – nonalcoholic steatohepatitis
  •         Various cancers – gastrointestinal, breast
  •         Osteoarthritis - back, hip, and knee
  •         Depression, anxiety

Patients typically appear obese on the exam.  Obesity is frequently concentrated in the abdominal region but may also affect other body parts. Patients with Cushing syndrome develop stria or purple skin lesions that appear like "stretch marks."  Patients with hypothyroidism or heart failure may have swelling in the legs.

How Is Obesity Diagnosed?

Obesity is diagnosed based on a patient's body mass index (BMI).  This is calculated by obtaining the patients' height in meters and weight in kilograms.  The weight is then divided by the height squared.  The following are the definitions for overweight, obesity, and severe obesity:

  •         Overweight BMI 25-29.9 kg/m2
  •         Obesity BMI ≥30 kg/m2
  •         Severe obesity BMI ≥40 kg/m2 or ≥35 kg/m2 with comorbidities

Commonly ordered blood tests include a CMP (comprehensive metabolic panel), thyroid function (TSH, free T4), CBC (complete blood cell count).  They will also usually check your cholesterol levels and screen for diabetes.

Some doctors will obtain an EKG (electrocardiogram) and ultrasound of the heart (echocardiogram) if they are concerned about heart disease.

Which Weight Loss Options are Available?

Obesity is first treated with diet and exercise.  This includes caloric restriction and incorporation of fruits and vegetables in the diet for weight loss.  This is important for cardiovascular protection and lowering cholesterol levels.  Patients may benefit from referral to a Nutritionist.  They are typically encouraged not to drink any alcohol or smoke cigarettes.

Individuals are also usually enrolled in an exercise program or routine physical activity regime.  This can be very difficult for most people as it requires a behavior change and dedication.  Some patients with comorbid depression or anxiety can benefit from referral to a psychotherapist.

Medications are also useful in the management of obesity.  Patients with diabetes mellitus type II should typically take Glucophage (metformin) to reduce blood sugar levels – metformin also helps patients reduce weight.

Alli (orlistat) is often beneficial in patients with obesity as it helps individuals lose weight and has beneficial effects on cholesterol.  Belviq (lorcaserin) is another medication for obese patients that cannot tolerate orlistat.

Qsymia (phentermine-topiramate) may be prescribed in men or postmenopausal women with obesity – these patients cannot have hypertension or coronary artery disease.  Lastly, the combination drug Contrave (bupropion-naltrexone) can also help reduce weight.

Patients with BMI ≥40 kg/m2 who have failed the above therapies may benefit from bariatric surgery.  Surgery may also be considered in individuals with BMI >35 kg/m2 with obesity-related complications such as hypertension, diabetes, or obstructive sleep apnea.


  1.     Ogden CL, Carroll MD, Lawman HG, et al. Trends in Obesity Prevalence Among Children and Adolescents in the United States, 1988-1994 Through 2013-2014. JAMA 2016; 315:2292. e72. - https://www.ncbi.nlm.nih.gov/pubmed/27272581
  2.     Kelly AS, Barlow SE, Rao G, et al. Severe obesity in children and adolescents: identification, associated health risks, and treatment approaches: a scientific statement from the American Heart Association. Circulation 2013; 128:1689. - https://www.ahajournals.org/doi/full/10.1161/cir.0b013e3182a5cfb3
  3.     Jensen MD, Ryan DH, Apovian CM, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. Circulation 2014; 129:S102. - https://www.ahajournals.org/doi/full/10.1161/01.cir.0000437739.71477.ee

Weight Loss Medication

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.