| Factors which decrease MAC | Factors which increase MAC |
| Advanced age | Childhood |
| Pregnancy (40% decrease) | Hyperthyroidism |
| Hypothermia | Hyperthermia |
| Acute alcohol intoxication | Chronic alcohol use |
| Drugs: benzodiazepines, opioids, muscle relaxants, central acting antihypertensives | Drugs: amphetamine, cocaine |
