Table 1 outlines the top five principal [1] causes of medical downgrading in the UK Regular armed forces on 01 April 2017 [2].

Table 1: Top five principals causes of medical downgrading
Causes	Percentage
Musculoskeletal Disorders & Injuries	59
Mental & Behavioural Disorders	11
Factors Influencing Health Status [3]	5
Ear & Mastoid Process Diseases	4
Clinical & Laboratory Findings [4]	3

Notes

1. Personnel who are medically downgraded or medically discharged can be affected by multiple injuries/illnesses. The principal causes is the main medical cause leading to the downgrading or discharge.
2. Based on UK Regular Armed Forces personnel who are medically downgraded as at 01 April 2017 and had a principal cause of downgrading that could be matched to the International Classification of Diseases and Related Health Problems version 10 (ICD-10).
3. Includes specific procedures such as fitting of prosthetics and donation of tissue. Also includes reasons for encountering the health services, for example for examination and investigation of a health concern and monitoring of pregnancy.
4. Includes symptoms and abnormal results of clinical tests that do not fit within other specific chapters or do not yet have a diagnosis. For example, nausea, non-specific rash, and abnormal blood test results.