Table 1 outlines the top five principal  causes of medical downgrading in the UK Regular armed forces on 01 April 2017 .
|Table 1: Top five principals causes of medical downgrading|
|Musculoskeletal Disorders & Injuries||59|
|Mental & Behavioural Disorders||11|
|Factors Influencing Health Status ||5|
|Ear & Mastoid Process Diseases||4|
|Clinical & Laboratory Findings ||3|
- 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.
- 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).
- 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.
- 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.