Woman with hypothyroidism wondering if it's a comorbidity for weight loss surgery

Is hypothyroidism a comorbidity for weight loss surgery?

Written on April 14, 2023 by Sendra Yang, PharmD, MBA. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

About weight loss surgery

Weight loss surgery, or bariatric surgery, can be used to lose weight and improve health issues related to being obese [1]. Weight loss surgery is intended as a therapeutic option as part of an overall management plan for obesity [2,3].

Types of weight loss surgery include gastric bypass, sleeve gastrectomy, gastric band, and duodenal switch [1,2]. The operations involve changing the digestive system by making your stomach smaller to make you feel full sooner and limiting the amount of food and drink you take at a time [1]. Other operations alter your small intestines, reducing the number of calories the body can absorb. Weight loss surgery can also affect gut bacteria, decreasing appetite and improving fat metabolism and insulin resistance. Changes in hormones can also occur with weight loss surgery.

Healthcare providers may recommend weight loss surgery for obesity treatment if other weight loss approaches have failed and the benefits of the surgery outweigh the risks [2,3]. Potential side effects of weight loss surgery include malabsorption and malnutrition, bile reflux, and gallstones [3]. Bariatric surgery can help you lose weight, regulate metabolism, and improve blood pressure, glucose levels, and cholesterol.

Criteria for weight loss surgery

Recommendations for weight loss surgery in obesity management are based on body mass index (BMI) and the presence of various comorbidities [2,3]. You may qualify for weight loss surgery if you fit one of these criteria [2,3]:

  • BMI of 40 kg/m^2 or more without any coexisting medical conditions
  • BMI greater than or equal to 35 kg/m^2 and one or more comorbidities
  • BMI of 30 to 34.9 kg/m^2 with diabetes or metabolic syndrome

Obesity and hypothyroidism

Obesity is defined as a BMI that exceeds 30 kg/m^2 and is associated with many prolonged diseases that pose health risks that may be improved with weight loss surgery [2-4]. The prevalence of obesity from 2017 to 2020 in the United States was approximately 42% [5]. Obesity is related to increased risks of diabetes, dyslipidemia, kidney disease, cardiovascular disease, and cancer [6]. Obesity is also linked to endocrine abnormalities that include thyroid dysfunction. Thyroid issues change your body weight, composition, temperature, and metabolism. Weight gain is a significant contributing factor to thyroid dysfunction [6,7]. An example of a thyroid dysfunction issue is a condition called hypothyroidism [6,7].

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What is hypothyroidism?

Hypothyroidism, also called underactive thyroid, is a condition where your thyroid gland does not produce enough thyroid hormone for your body [8]. The thyroid is a small, butterfly-shaped gland in the front of your neck. The thyroid hormone controls how your body uses energy and affects almost every organ. Not having enough thyroid hormone slows down various functions in your body.

Causes of hypothyroidism

Obesity is thought to be a contributory secondary cause of hypothyroidism [7]. There are several other causes of hypothyroidism, including [8,9]:

  • Hashimoto’s disease
  • Inflammation of the thyroid
  • Congenital hypothyroidism
  • Surgical removal of part or all of the thyroid
  • Radiation treatment of the thyroid
  • Pituitary gland disorders
  • Too much or not enough iodine in the diet

Hypothyroidism symptoms

The symptoms of hypothyroidism can vary for different people [8]. Common symptoms include [8,9]:

  • Weight gain
  • Fatigue
  • Joint and muscle pain
  • Intolerance of cold
  • Decreased heart rate
  • Issues with menstrual cycles or fertility
  • Dry skin and hair

Hypothyroidism treatment options

If your hypothyroidism is left untreated, you can gain a significant amount of weight [9]. However, if your condition is treated, your weight can be lowered. Hypothyroidism is often treated with medications that replace the amount of hormone your thyroid is not producing to normalize the levels in your body [9]. It’s also essential that you manage your weight by eating a healthy, well-balanced diet with regular exercise.

An option that can be considered as part of hypothyroidism therapy is weight loss surgery [10-12]. A study including about 100 patients with an average BMI of 43.7 kg/m^2 who underwent weight loss surgery showed a favorable impact on thyroid function and reduced thyroid medication dosages [10]. More research is still needed to better understand the effect of weight loss surgery in patients with hypothyroidism.

Hypothyroidism is a comorbidity for weight loss surgery

Since hypothyroidism is an obesity-related condition, it can be considered a comorbidity for weight loss surgery [6,7]. A reduction in body weight has been found to be helpful in managing hypothyroidism [10-12]. However, hypothyroidism alone may not be sufficient to qualify you for weight loss surgery [2,3].

Speak with your healthcare provider

Weight loss surgery is a therapeutic option for obesity with various benefits. Losing weight can contribute to positive improvements in your hypothyroid condition. However, you and your healthcare provider must consider your comorbid diseases, BMI, and risks to determine if weight loss surgery is the best choice for you.

It is also a good idea to consult with a healthcare provider before starting any therapeutic options for weight loss. You can discuss your hypothyroidism, obesity-related conditions, or any other questions you may have with your clinician. Additionally, if you are concerned with your weight and would like to speak with a healthcare provider about your health goals, consider an online weight loss telehealth visit via Everlywell. You can get monthly support from a certified clinician to optimize a care plan for you.

Obesity-related comorbidities: what comorbidities are related to obesity?

What is comorbidity?

Managing obesity in patients with comorbidities: what to know


  1. Weight-loss (bariatric) surgery. National Institute of Diabetes and Digestive and Kidney Diseases. URL. Accessed April 13, 2023.
  2. Wharton S, Lau DCW, Vallis M, et al. Obesity in adults: a clinical practice guideline. CMAJ. 2020;192(31):E875-E891. doi: 10.1503/cmaj.191707. URL.
  3. Bariatric (weight loss) surgery: Types & requirements. Cleveland Clinic. URL. Accessed April 11, 2023.
  4. Stahl JM, Malhotra S. Obesity surgery indications and contraindications. 2022. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023. URL.
  5. Adult obesity facts. Centers for Disease Control and Prevention. URL. Published May 17, 2022. Accessed April 13, 2023.
  6. Biondi B. Thyroid and obesity: an intriguing relationship. J Clin Endocrinol Metab. 2010;95(8):3614-7. doi: 10.1210/jc.2010-1245. URL.
  7. Sanyal D, Raychaudhuri M. Hypothyroidism and obesity: An intriguing link. Indian J Endocrinol Metab. 2016;20(4):554-7. doi: 10.4103/2230-8210.183454. URL.
  8. Hypothyroidism (underactive thyroid). National Institute of Diabetes and Digestive and Kidney Diseases. URL. Accessed April 13, 2023.
  9. Hypothyroidism: Symptoms, causes, treatment & medication. Cleveland Clinic. URL. Accessed April 13, 2023.
  10. Zendel A, Abu-Ghanem Y, Dux J, Mor E, Zippel D, Goitein D. The impact of bariatric surgery on thyroid function and medication use in patients with hypothyroidism. Obes Surg. 2017;27(8):2000-2004. doi: 10.1007/s11695-017-2616-7. URL.
  11. Rudnicki Y, Slavin M, Keidar A, et al. The effect of bariatric surgery on hypothyroidism: Sleeve gastrectomy versus gastric bypass. Surg Obes Relat Dis. 2018;14(9):1297-1303. doi: 10.1016/j.soard.2018.06.008. URL.
  12. Neves JS, Castro OS, Souteiro P, et al; AMTCO Group. Effect of weight loss after bariatric surgery on thyroid-stimulating hormone levels in patients with morbid obesity and normal thyroid function. Obes Surg. 2018;28(1):97-103. doi: 10.1007/s11695-017-2792-5. URL.
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