5B81

ICD-11 MMS 2026-01

Obesity

Description

Obesity is a chronic complex disease defined by excessive adiposity that can impair health. It is in most cases a multifactorial disease due to obesogenic environments, psycho-social factors and genetic variants. In a subgroup of patients, single major etiological factors can be identified (medications, diseases, immobilization, iatrogenic procedures, monogenic disease/genetic syndrome). Body mass index (BMI) is a surrogate marker of adiposity calculated as weight (kg)/height² (m²). The BMI categories for defining obesity vary by age and gender in infants, children and adolescents. For adults, obesity is defined by a BMI greater than or equal to 30.00 kg/m² and there are three levels of severity in recognition of different management options.

Exclusions from above levels

  • 18 – Pregnancy, childbirth or the puerperium
  • http://id.who.int/icd/entity/1004987305 – Transitory endocrine or metabolic disorders specific to fetus or newborn

Child codes

  • 5B81.0 – Obesity due to energy imbalance
  • 5B81.1 – Drug-induced obesity
  • 5B81.Y – Other specified obesity
  • 5B81.Z – Obesity, unspecified

Foundation children elsewhere

  • 7A42.0 – Obesity hypoventilation syndrome
  • LD29 – Syndromes with obesity as a major feature

Sibling codes

  • 5B80 – Overweight or localised adiposity

Foundation entity

Obesity – http://id.who.int/icd/entity/149403041

Allowed postcoordination axes

Part of: 05: Endocrine, nutritional or metabolic diseases