| Abbreviation | Definition |
|---|---|
| MHC | Major Histacompatability Complex |
| MHN | Managed Health Network, Inc. |
| MHP | Mercy Health Plans |
| MHQ | Material Happyness Quotient |
| MHQ | Medical History Questionnaire |
| MHR | Maximal heart rate |
| MHR | Maximum Heart Rate |
| MHS | Mayo Health System |
| MHS | Memorial Healthcare System |
| MHS | Multi-Health Systems |
| MHV | Mechanical Heart Valve |
| MI | Mental illness |
| MI | Mitral Insufficiency |
| MI | Myocardial Infarction |
| MIA | BuliMIA |
| MIBS | Minimally Invasive Brain Stimulation |
| MIC | Minimal inhibitory concentration |
| MIC | Minimum Inhibitory Concentration |
| MICA | Mentally Ill, Chemically Addicted |
| MI-CK | MItochondrial Creatine Kinase |