Healthcare provider explaining to patient what a comorbidity is

What is comorbidity?

Written on April 14, 2023 by Theresa Vuskovich, DMD. 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

Comorbidity means an individual has multiple chronic medical conditions [1]. When you have multiple medical conditions, you are at a greater risk of contracting infectious diseases like COVID-19 [2,3]. In addition, you're predisposed to developing more health problems. This article explains the answer to the question "What is a comorbidity?" including common examples of comorbidities and why they occur.

What are common examples of comorbidities?

The most common comorbidities are hypertension and diabetes [6]. It is important to note that the terms comorbidity and multimorbidity are often used interchangeably. However, multimorbidity is when you have more than two chronic conditions [4,5]. The following are examples of comorbidities [5, 7-14]:

  • Hypertension and heart failure: Hypertension (high blood pressure) commonly occurs with other diseases. A systolic blood pressure of 130 or higher and a diastolic blood pressure of over 80 is considered high blood pressure. Hypertension can cause the development of other chronic conditions, most commonly heart failure [7]. The hazard ratio (how often a particular event happens in one group compared to another over time) of developing heart failure is twice as high among men and three times as high among women with high blood pressure [7].
  • Arthritis and heart disease: Arthritis is a group of diseases associated with joint pain and stiffness [5]. The most common type of arthritis is osteoarthritis, which occurs due to the natural wear and tear of aging. Another type of arthritis is rheumatoid arthritis which is an autoimmune condition. As a result of arthritis, a person becomes less active, which can lead to heart problems. Low-impact exercises such as swimming and walking are two exercise options for people with arthritis.
  • Obesity and type 2 diabetes (T2DM): 90% of people with T2DM are overweight or obese [12]. T2DM can cause obesity, and obesity can worsen symptoms of T2DM. T2DM occurs when the body becomes unresponsive to insulin, resulting in high blood sugar. High blood sugar can damage your arteries and nerves, resulting in additional medical conditions. If you have T2DM and obesity, losing 5% of your body weight can improve your insulin sensitivity [11].
  • Obesity and obstructive sleep apnea (OSA): People with obesity are also prone to OSA [11]. OSA occurs when your upper airway becomes blocked during sleep. When an individual is diagnosed with OSA, the first line of treatment is usually weight loss [13]. Obesity and OSA have a bidirectional relationship, meaning OSA can cause obesity, and obesity can cause OSA.
  • Chronic obstructive pulmonary disease (COPD) and cancer: COPD is a group of diseases that impair lung function. The primary cause of COPD is smoking, but COPD can also occur due to environmental pollutants. COPD and lung cancer are common comorbid conditions [9,10]. While COPD and lung cancer share a common risk factor (i.e., smoking), COPD is an independent risk factor for lung cancer [14].

Everlywell Weight Loss Support

Why do comorbidities occur?

The natural aging process is a primary reason for comorbidities [15]. As the population ages, comorbidity and multimorbidity will become more prevalent. In 2019, 84% of patients in the hospital had comorbid conditions [6]. Comorbidities are caused by the following factors [1]:

  1. Shared risk factors: Many comorbid conditions share common risk factors. For example, smoking is a risk factor for lung cancer and COPD.
  2. Shared causes: Obesity can cause multiple diseases leading to comorbidities and multimorbidities [11-13]. Obesity can cause T2DM, heart disease, OSA, osteoarthritis, and stroke, to name a few [11].
  3. Complication of a chronic disease: A comorbid condition can occur as a complication of a chronic disease. A comorbidity is not a complication. Complications are side effects or medical problems resulting from a disease or treatment. The relationship between arthritis and heart disease is an example. Arthritis can lead to physical inactivity, leading to heart disease as a complication.

How can you prevent comorbidities?

You can minimize your risk of comorbidities by:

  • Maintaining a healthy lifestyle: You can maintain a healthy lifestyle by eating a plant-based diet and limiting alcohol. Incorporate physical activity into your day and exercise for at least 150 minutes weekly. Weight management is one of the most important aspects of maintaining a healthy lifestyle.
  • Being proactive: Make sure you attend your regular health screenings and remain mindful of your body. Everlywell's at-home lab tests can help you track your health over time.
  • Speaking with your healthcare provider: If you have concerns or questions about your risk for a comorbidity, speak with a healthcare provider. Your healthcare provider can monitor your symptoms over time to prevent or manage chronic conditions.

Speak with a healthcare provider about comorbidities

Weight loss telehealth via Everlywell can help you learn more about your weight and potential comorbidities. These telehealth visits are synchronous, allowing you to speak directly to a healthcare provider from home. Your healthcare provider can assess your health issues, suggest lab tests, and personalize your care.

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

Managing obesity in patients with comorbidities: what to know

Comorbidities for weight loss surgery


  1. Valderas JM, Starfield B, Sibbald B, Salisbury C, Roland M. Defining comorbidity: implications for understanding health and health services. Ann Fam Med. 2009;7(4):357-363. doi:10.1370/afm.983. URL
  2. Comorbidities the CDC classifies as risk factors for severe COVID-19. URL. Accessed April 11, 2023
  3. CDC. Underlying medical conditions associated with higher risk for severe COVID-19: Information for healthcare professionals. Centers for Disease Control and Prevention. URL. Published March 21, 2023. Accessed April 11, 2023.
  4. Harrison C, Fortin M, van den Akker M, et al. Comorbidity versus multimorbidity: Why it matters. J Multimorb Comorb. 2021;11:2633556521993993. Published 2021 Mar 2. doi:10.1177/2633556521993993. URL
  5. Comorbidities. URL. Published August 4, 2022. Accessed April 11, 2023.
  6. Owens PL, Liang L, Barrett ML, Fingar KR. Comorbidities Associated With Adult Inpatient Stays, 2019. URL. Published 2022. Accessed April 11, 2023.
  7. Bozkurt B, Aguilar D, Deswal A, Dunbar SB, Francis GS, Horwich T, Jessup M, Kosiborod M, Pritchett AM, Ramasubbu K, Rosendorff C, Yancy C. Contributory Risk and Management of Comorbidities of Hypertension, Obesity, Diabetes Mellitus, Hyperlipidemia, and Metabolic Syndrome in Chronic Heart Failure: A Scientific Statement From the American Heart Association. Circulation. 2016;134(23):CIR.000000000000. doi:10.1161/cir.0000000000000450. URL
  8. Boersma P, Black LI, Ward BW. Prevalence of multiple chronic conditions among US adults, 2018. Prev Chronic Dis. 2020;17:E106. doi:10.5888/pcd17.200130. URL
  9. Fowler H, Belot A, Ellis L, Maringe C, Luque-Fernandez MA, Njagi EN, Navani N, Sarfati D, Rachet B. Comorbidity prevalence among cancer patients: a population-based cohort study of four cancers. BMC Cancer. 2020;20(1). doi:10.1186/s12885-019-6472-9. URL
  10. Renzi C, Kaushal A, Emery J, Hamilton W, Neal RD, Rachet B, Rubin G, Singh H, Walter FM, de Wit NJ, Lyratzopoulos G. Comorbid chronic diseases and cancer diagnosis: disease-specific effects and underlying mechanisms. Nat Rev Clin Oncol. 2019 Dec;16(12):746-761. doi: 10.1038/s41571-019-0249-6. Epub 2019 Jul 26. PMID: 31350467. URL
  11. Lim Y, Boster J. Obesity and Comorbid Conditions. StatPearls Publishing; 2023. URL
  12. Grant B, Sandelson M, Agyemang-Prempeh B, Zalin A. Managing obesity in people with type 2 diabetes. Clinical Medicine. 2021;21(4):e327-e231. doi:10.7861/clinmed.2021-0370. URL
  13. Jehan S, Zizi F, Pandi-Perumal SR, et al. Obstructive Sleep Apnea and Obesity: Implications for Public Health. Sleep Med Disord. 2017;1(4):00019. URL
  14. Durham AL, Adcock IM. The relationship between COPD and lung cancer. Lung Cancer. 2015;90(2):121-127. doi:10.1016/j.lungcan.2015.08.017. URL
  15. Ording AG, Sørensen HT. Concepts of comorbidities, multiple morbidities, complications, and their clinical epidemiologic analogs. Clin Epidemiol. 2013;5:199-203. Published 2013 Jul 1. doi:10.2147/CLEP.S45305. URL
Everlywell makes lab testing easy and convenient with at-home collection and digital results in days. Learn More