Essential 10 major diagnostic categories (MDC) for functional primary clinics
| MDC 1 | Nervous system |
| MDC 3 | Ear, nose, mouth, and throat |
| MDC 4 | Respiratory system |
| MDC 5 | Circulatory system |
| MDC 6 | Digestive system |
| MDC 8 | Musculoskeletal system and connective tissue |
| MDC 9 | Skin, subcutaneous tissue, and breast |
| MDC 10 | Endocrine, nutritional, and metabolic system |
| MDC 11 | Kidney and urinary tract |
| MDC 19 | Mental diseases and disorders |