

| Acronym | Sense | Language | Topics | 
|---|---|---|---|
| MMI | Medicus Mundi Italia | In Italian | → Organizations and associations | 
| MMM | Myélofibrose avec Métaplasie Myéloïde | In French | → Blood and circulatory system → Pathology | 
| MMS | Medical Mission Sisters | In English | → Roman catholic church | 
| MMS | Mini Mental Slate | In English | → Neurology | 
| MMSE | Mini-Mental State Examination | In English | |
| MMSE | Mini Mental State Examination | In English | → Neurology | 
| MMT | Médecins Maîtres-Toile | In French | → Networks, communication → Organizations and associations | 
| MMTV | Mouse Mammary Tumor Virus | In English | → Virology → Oncology | 
| MMW | Münchener Medizinische Wochenschrift | In German | → Serial publications, periodicals | 
| MNA | Mini Nutritional Assessment | In English | → Nutrition | 
| MO-MED | Mobile Information Engineering & E-Med Systems | In English | → Telecommunications | 
| MoBiMed | Molekulare Bildgebung in der Medizin | In German | → Biological sciences | 
| MODY | Maturity-Onset Diabetes of the Young | In English | → Physiology → Pathology | 
| MOE | Munduko Osasun Erakundea = MOS | Monda Organiz(aĵ)o pri Sano | In Esperanto = WHO | World Health Organization | In English = OMS | Organisation Mondiale de la Santé | In Esperanto = OMS | Organizzazione Mondiale della Sanità | In Italian = WGO | Wêreldgesondheidsorganisasie | In Afrikaans = OMS | Organización Mundial de la Salú | In Asturian = СЗО | Световната здравна огранизация | In Bulgarian = SZO | Světová zdravotnická organizace | In Czech = OMS | Organització Mundial de la Salut | In Catalan = OMS | Organización Mundial de la Salud | In Spanish = MTO | Maailma Terviseorganisatsioon | In Estonian = OMS | Organisacion mondiâla de la sandât | In Franco-Provençal = OMS | Organización Mundial da Saúde | In Galician = SZO | Svjetska zdravstvena organizacija | In Croatian = RTD | Rêxistina Tendurustiyê ya Dinyayê | In Kurdish = UMS | Urganizazziun mundiala da la Santaa | In Lombard = PSO | Pasaulio sveikatos organizacija | In Lithuanian = PVO | Pasaules veselības organizācija | In Latvian = ÜST | Ümumdünya Səhiyyə Təşkilatı | In Turkish | In Basque | → United Nations | 
| MoMLV | Moloney Murine Leukemia Virus | In English | → Virology → Infectious diseases | 
| MORD | Medical Operations Requirements Document | In English | |
| MORT | Management Oversight and Risk Tree | In English | → Management → Accidents, risks, safety | 
| MOS | Monda Organiz(aĵ)o pri Sano = MOE, WHO, OMS, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Esperanto | → United Nations | 
| MOSES | Mobile Safety System | In English | → Engineering, technology → Accidents, risks, safety | 
| MPGN | Membranoproliferative Glomerulonephritis | In English | → Pathology | 
| MPH | Master of Public Health | In French | → Higher education, universities → Public health and hygiene | 
| MPOC | Maladie Pulmonaire Obstructive Chronique | In French | → Pathology | 
| MPOC | Maladie Pulmonaire Obstructive Chronique = BPCO | Broncho-Pneumopathie Chronique Obstructive | In French = COPD | Chronic Obstructive Pulmonary Disease | In English = COLD | Chronic Obstructive Airway Disease | In English = COAD | Chronisch obstruktive Atemwegserkrankung | In German = EPOC | Enfermedad Pulmonar Obstructiva Crónica | In Spanish = BPCO | Broncopneumopatia Cronica Ostruttiva | In Italian = DPOC | Doença Pulmonar Obstrutiva Crónica | In Portuguese = KOAH | Kronik Obstrüktif Akciğer Hastalığı | In Turkish | In French | → Chest diseases | 
| MPPS | Mammary Gland Physiology and Pathology Society | In English | → Organizations and associations → Physiology → Pathology → Mammals | 
| MPR | Moto-Pompe Remorquable | In French | → Automobile manufacturing → Firefighting | 
| MPS | Mission Permanente de Sécurité | In French | → Accidents, risks, safety | 
| MR | Magnetska ili magnetna rezonancija | In Croatian | → Nuclear, atomic, and molecular physics | 
| MRC | Medical Research Council | In English | → Organizations and associations | 
| MRD | Minimal Residual Disease | In English | → Pathology | 
| MRI | Magnetic Resonance Imagery = IRM | Imagerie par Résonance Magnétique | In French | In English | → Nuclear, atomic, and molecular physics | 
| MRT | Magnetresonanz-Tomografie = MRT | Magnetresonanstomografi | In Swedish | In German | → Nuclear, atomic, and molecular physics | 
| MRT | Magnetresonanstomografi = (look above) | In Swedish | → Nuclear, atomic, and molecular physics | 
| MRZ | Medizinisches Rechenzentrum | In German | → Computer science | 
| MS | Multiple Sclerosis | In English | → Neurology | 
| MS | Ministerul Sănătăţii | In Romanian | → Central administration → Public health and hygiene | 
| MSBCIA | Macedonian Society for Basic, Clinical Immunology and Allergology | In English | → Organizations and associations → Immunology and allergy | 
| MSBM | Maîtrise de Sciences Biologiques et Médicales | In French | → Higher education, universities → Biological sciences | 
| MSE | Medical Support Equipment | In English | |
| MSF | Médecins Sans Frontières (www.msf.fr) | In French | → Associations | 
| MSHA | Mine Safety and Health Administration | In English | → Public administration, government → Accidents, risks, safety | 
| MSJ | Medical Sisters of Saint Joseph | In English | → Roman catholic church | 
| MSMR | Massachusetts Society for Medical Research (www.msmr.org) | In English | → Organizations and associations → United States | 
| MSPP | Ministère de la Santé Publique et de la Population | In French | → Central administration → Public health and hygiene | 
| MSTP | Medical Scientist Training Program | In English | → Education | 
| MT | Medical Technology | In English | |
| MTEV | Maladie Thromboembolique Veineuse | In French | → Blood and circulatory system | 
| MTF | Medical Treatment Facility | In English | |
| MTO | Maailma Terviseorganisatsioon = MOE, MOS, WHO, OMS, WGO, СЗО, SZO, RTD, UMS, PSO, PVO, ÜST (look above) | In Estonian | → United Nations | 
| MUG | Medizinische Universität Graz | In German | → Higher education, universities | 
| MUMPS | Massachusetts General Hospital Utility Multi-Programming System | In English | → Programming languages → United States | 
| MUSE | Medicated Urethral System for Erection | In English | → 3926 → Urology | 
| MUST | Modelling the Use and Safety of Transport = MUST | Modélisation de l'Usage et de la Sécurité des Transports | In French | In English | → Accidents, risks, safety → Vehicle engineering → Transport and postal services | 
| MUW | Medizinische Universität Wien | In German | → Higher education, universities → Austria | 
| MVL | Multilamellar Vesicle | In English | → Biotechnology → Pharmacology, toxicology | 
| MVMA | Maryland Veterinary Medical Association (www.mdvma.org) | In English | → Associations → Veterinary medicine | 
| MVO | Maladie Veino-Occlusive | In French | → Blood and circulatory system → Pathology | 
| MW | Medische Wetenschappen | In Dutch | |
| NABR | National Association for Biomedical Research (www.nabr.org) | In English | → Associations → Biological sciences | 
| NACCP | National Association of Child Care Professionals | In English | → Associations → Pediatry | 
| NAHIS | National Animal Health Information System | In English | → Veterinary medicine | 
| NAN | Nombre Absolu de Neutrophiles | In French | → Blood and circulatory system | 
| NANB | Nurses Association of New Brunswick | In English | → Associations → Canada | 
| NAPCC | National Animal Poison Control Center | In English | → Organizations and associations → Pharmacology, toxicology → Veterinary medicine | 
| NASH | Nicht-alkoholische Steatohepatitis | In German | → Pathology | 
| NASS | North American Spine Society | In English | → Organizations and associations | 
| NAVCA | North American Veterinary College Administrators | In English | → Organizations and associations → Veterinary medicine | 
| NAVP | National Association of Veterinary Physiotherapists (www.navp.org.uk) | In English | → Associations → Veterinary medicine | 
| NAVP | National Association of Vision Professionals | In English | → Associations → Ophthalmology | 
| NBIC | Nanotechnologies, Biologie, Information, Cognition | In French | → Engineering, technology → Biotechnology → Computer science → Neurology | 
| NCA | National Care Association (www.nca.gb.com) | In English | → Associations → Social welfare | 
| NCI | National Cancer Institute | In English | → Organizations and associations → Oncology | 
| NCM | Neural Control of Movement Society (http://ncm-society.org) | In English | → Organizations and associations → Neurology | 
| NCNM | National College of Natural Medicine | In English | → Higher education, universities | 
| NCRR | National Center for Research Resources (www.ncrr.nih.gov) | In English | → Research institutes → Biological sciences | 
| NDA | New Drug Application | In English | → Pharmacology, toxicology | 
| NDL | National Diet Library | In English | → Libraries → Nutrition | 
| NEJM | New England Journal of Medicine | In English | → Serial publications, periodicals | 
| NEM | Néoplasie Endocrinienne Multiple | In French | → Oncology → Endocrinology → Physiology | 
| NEOBRAIN | Neonatal Estimation Of Brain Damage Risk And Identification of Neuroprotectants | In English | → Neurology → Obstetrics | 
| NERF | Neuropôle de Recherche Francilien | In French | → Research institutes → Neurology → France | 
| NERI | Norepinephrine Reuptake Inhibitor = NRI | Norepinephrine Reuptake Inhibitor | In English = NRI | Noradrenaline Reuptake Inhibitor | In English = ARI | Adrenergic Reuptake Inhibitor | In English | In English | → Pharmacology, toxicology → Neurology | 
| NET | Nécrolyse Épidermique Toxique = TEN | Toxic Epidermal Necrolysis | In English | In French | → Dermatology → Immunology and allergy → Pharmacology, toxicology | 
| NETT | National Emphysema Treatment Trial | In English | → Chest diseases | 
| NGF | Nerve Growth Factor | In English | → Hormones → Neurology" | 
| NHC | Nouvel Hôpital Civil | In French | |
| NHC | National Heart Centre (www.nhc.com.sg) | In English | → Cardiology | 
| NHF | National Hemophilia Foundation | In English | → Foundations → Blood and circulatory system → Pathology | 
| NHLBI | National Heart, Lung, and Blood Institute (www.nhlbi.nih.gov) | In English | → Research institutes → Blood and circulatory system → Cardiology | 
| NHTSA | National Highway Traffic Safety Association | In English | → Associations → Accidents, risks, safety → Transport and postal services | 
| NHTSA | National Highway Traffic Safety Administration (www.nhtsa.dot.gov) | In English | → Central administration → Accidents, risks, safety → Transport and postal services | 
| NIAH | National Institute of Animal Health | In English | → Organizations and associations → Veterinary medicine | 
| NiC | NeuroImaging Center | In English | → Diagnostics → Neurology | 
| NICE | National Institute for Health and Clinical Excellence | In English | |
| NIDDK | National Institute of Diabetes and Digestive and Kidney Diseases | In English | → Research institutes → Physiology → Pathology | 
| NIDRR | National Institute on Disability and Rehabilitation Research | In English | → Research institutes | 
| NIFTE | National Initiative for Telehealth | In English | |
| NIH | National Institutes of Health (www.nih.gov) | In English | → Research institutes → Biological sciences | 
| NIMH | National Institute of Mental Health | In English | → Neurology | 
| NIOSH | National Institute for Occupationnal Safety and Health | In English | → Accidents, risks, safety → Labour, labour economics | 
| NIOSH | National Institute for Occupational Safety and Health | In English | → Accidents, risks, safety → Labour, labour economics | 
| NIPS | National Institute for Physiological Sciences | In English | → Research institutes → Physiology | 
| NKI-AVL | Nederlands Kanker Instituut - Antoni van Leeuwenhoek Ziekenhuis | In Dutch | → Research institutes → Oncology → Netherlands | 
| NLM | National Library of Medicine (www.nlm.nih.gov) | In English | → Libraries | 
| NMC | Nursing and Midwifery Council | In English | → Organizations and associations | 
| NMC | National Mastitis Council (www.nmconline.org) | In English | → Organizations and associations → Veterinary medicine → Agricultural sciences | 
| NMD | Nuclear Medicine | In English | |
| NMI | Naturwissenchaftlich-Medizinisches Institut | In German | → Research institutes → Biological sciences | 
| NMMBC | Neuropathie Motrice Multifocale à Bloc de Conduction | In French | → Neurology | 
| NMR | Nuclear Magnetic Resonance = RMN | Résonance Magnétique Nucléaire | In French = RMN | Ressonància Magnètica Nuclear | In Catalan = RMN | Risonanza Magnetica Nucleare | In Italian = תמ"ג | תהודה מגנטית גרעינית | In Hebrew = ЯМР | Я́дерного магни́тного резона́нса | In Russian = НМР | Нуклеарна магнетна резонанција | In Serbian | In English | → Nuclear, atomic, and molecular physics → Nuclear technology | 
| NMVMA | New Mexico Veterinary Medical Association (www.nmvma.org) | In English | → Associations → Veterinary medicine → Mexico | 
| NN | Neural Networks | In English | → Serial publications, periodicals → Computer-based techniques → Neurology | 
| NÖGKK | Niederösterreichische Gebietskrankenkasse (www.noegkk.at) | In German | → Insurance → Austria | 
| NÖGUS | Niederösterreichischer Gesundheits- und Sozialfonds (www.noegus.at) | In German | → Social welfare → Austria | 
| NPH | Neutral Protamine Hagedorn | In English | → Cardiology | 
| NRA | Norepinephrine Releasing Agent | In English | → Pharmacology, toxicology → Neurology | 
| NRI | Needham Research Institute (www.nri.cam.ac.uk) | In English | → Research institutes → History → Engineering, technology → United Kingdom | 
| NRI | Norepinephrine Reuptake Inhibitor = NERI, ARI (look above) | In English | → Pharmacology, toxicology → Neurology | 
| NRI | Noradrenaline Reuptake Inhibitor = NERI, ARI (look above) | In English | → Pharmacology, toxicology → Neurology | 
| NRK | Nederlandse Rode Kruis | In Dutch | → Organizations and associations → Netherlands | 
| NSLC | Non-Small cell Lung Carcinoma | In English | → Chest diseases → Oncology | 
| NTA | National Treatment Agency for Substance Misuse | In English | → Personal health and hygiene | 
| NTSC | Nuclear Technology Safety Center | In English | → Accidents, risks, safety → Nuclear technology | 
| nvMCJ | Nouveau variant de la Maladie de Creutzfeldt-Jakob | In French | → Neurology | 
| NVTG | Nederlandse Vereniging voor Tropische Geneeskunde | In Dutch | → Organizations and associations → Netherlands | 
| ÖÄGMM | Österreichische Ärztegesellschaft für Manuelle Medizin (www.manuellemedizin.org) | In German | → Organizations and associations → Austria | 
| ÖÄK | Österreichische Ärztekammer (www.aerztekammer.at) | In German | → Organizations and associations → Austria | 
| OAP | Œdème Aigu Pulmonaire | In French | → Chest diseases | 
| OASM | Office of Aerospace Medicine | In English | → Aeronautics, aircraft → Astronautics | 
| OAVT | Ontario Association of Veterinary Technicians (www.oavt.org) | In English | → Associations → Veterinary medicine → Canada | 
| OBG | Onlay Bone Graft | In English | → Dentistry | 
| ÖBIG | Österreichisches Bundesinstitut für Gesundheitswesen | In German | → Central administration → Public health and hygiene → Austria | 
| OBNT | Ordre de Base National des Transmissions | In French | → Telecommunications → Firefighting | 
| OBS | Operational Bioinstrumentation System | In English | |
| OBS | Operational Biomedical System | In English | |
| OBVP | Österreichischer Bundesverband für Psychotherapie (www.psychotherapie.at) | In German | → Organizations and associations → Psychology → Neurology → Austria | 
| OCD | Obsessive Compulsive Disorder | In English | → Psychology → Neurology | 
| OCDU | Outpatient Clinical Decision Unit | In English | → 61608 | 
| ÖDG | Österreichische Diabetes-Gesellschaft (www.oedg.org) | In German | → Organizations and associations → Physiology → Pathology → Austria | 
| OEC | Olfactory Ensheathing Cell | In English | → Anatomy | 
| OECI | Organization of European Cancer Institutes (http://https://oeci.eu/) | In English | → Organizations and associations → Research institutes → Oncology → Europe | 
| OEGGG | Österreichische Gesellschaft für Gynäkologie und Geburtshilfe (www.oeggg.at) | In German | → Organizations and associations → Gynaecology → Obstetrics → Austria | 
| OES | Occupational and Environmental Safety | In English | → Labour, labour economics → Environmental protection | 
| OFA | Orthopedic Foundation for Animals (www.offa.org) | In English | → Foundations → Veterinary medicine | 
| OFPS | Office of Fire Protection and Safety | In English | → Accidents, risks, safety | 
| ÖGA | Österreichische Gesellschaft für Akupunktur (www.akupunktur.at) | In German | → Organizations and associations → Pharmacology, toxicology → Austria | 
| ÖGAI | Österreichische Gesellschaft für Allergologie und Immunologie (www.oegai.org) | In German | → Organizations and associations → Immunology and allergy → Austria | 
| ÖGAM | Österreichische Gesellschaft für Allgemeinmedizin (www.oegam.at) | In German | → Organizations and associations → Austria | 
| ÖGAM | Österreichische Gesellschaft für Allgemein- und Familienmedizin = ELNA | Esperanto-Ligo de Nord-Ameriko | In Esperanto = ELNA | Esperanto League for North America | In English | In German | → Organizations and associations → Austria | 
| ÖGARI | Österreichische Gesellschaft für Anaesthesiologie, Reanimation und Intensivmedizin (www.oegari.at) | In German | → Organizations and associations → Traumatology → Anesthesiology → Austria | 
| OGD | Oesophago-Gastro-Duodénoscopie | In French | → Diagnostics | 
| ÖGDV | Österreichische Gesellschaft für Dermatologie und Venerologie (www.oegdv.at) | In German | → Organizations and associations → Dermatology → Austria | 
| ÖGGG | Österreichische Gesellschaft für Geriatrie und Gerontologie (www.geriatrie-online.at) | In German | → Organizations and associations → Gerontology → Austria | 
| ÖGGH | Österreichische Gesellschaft für Gastroenterologie und Hepatologie (www.oeggh.at) | In German | → Organizations and associations → Pathology → Austria | 
| ÖGHMP | Österreichische Gesellschaft für Hygiene, Mikrobiologie und Präventivmedizin (www.oeghmp.at) | In German | → Organizations and associations → Personal health and hygiene → Public health and hygiene → Microbiology → Austria | 
| ÖGHO | Österreichische Gesellschaft für Hämatologie und Onkologie (www.oegho.at) | In German | → Organizations and associations → Blood and circulatory system → Oncology → Austria | 
| ÖGIM | Österreichische Gesellschaft für Innere Medizin (www.oegim.at) | In German | → Organizations and associations → Austria | 
| ÖGK | Österreichisches Grünes Kreuz (www.gruenes-kreuz.org) | In German | → Organizations and associations → Austria | 
| OGKA | Österreichische Gesellschaft für kontrollierte Akupunktur (www.ogka.at) | In German | → Organizations and associations → Pharmacology, toxicology → Austria | 
| ÖGKC | Österreichische Gesellschaft für klinische Chemie | In German | → Organizations and associations → Biochemistry, biophysics → Pharmacology, toxicology → Austria | 
| ÖGKJ | Österreichische Gesellschaft für Kinder- und Jugendheilkunde (https://www.paediatrie.at/) | In German | → Organizations and associations → Pediatry → Austria | 
| ÖGLUT | Österreichische Gesellschaft für Lungenerkrankungen und Tuberkulose (www.oeglut.at) | In German | → Organizations and associations → Chest diseases → Infectious diseases → Austria | 
| ÖGN | Österreichische Gesellschaft für Neurologie (www.oegn.at) | In German | → Organizations and associations → Neurology → Austria | 
| ÖGN | Österreichische Gesellschaft für Nuklearmedizin (www.ogn.at) | In German | → Organizations and associations → Austria | 
| ÖGP | Österreichische Gesellschaft für Pneumologie (www.ogp.at) | In German | → Organizations and associations → Chest diseases → Austria | 
| ÖGPB | Österreichische Gesellschaft für Neuropsychopharmakologie und Biologische Psychiatrie (www.oegpb.at) | In German | → Organizations and associations → Pharmacology, toxicology → Neurology → Psychiatry → Austria | 
| ÖGPH | Österreichische Gesellschaft für Public Health (www.oeph.at) | In German | → Organizations and associations → Public health and hygiene → Austria | 
| ÖGPMR | Österreichische Gesellschaft für Physikalische Medizin und Rehabilitation (www.oegpmr.at) | In German | → Organizations and associations → Austria | 
| ÖGRM | Österreichische Gesellschaft für Reproduktionsmedizin und Endokrinologie (www.oegrm.at) | In German | → Organizations and associations → Gynaecology → Austria | 
| ÖGRO | Österreichische Gesellschaft für Radioonkologie (www.oegro.com) | In German | → Organizations and associations → Oncology → Austria | 
| ÖGS | Österreichische Gesellschaft für Senologie (www.senologie.at) | In German | → Organizations and associations → Gerontology → Austria | 
| ÖGSMSF | Österreichische Gesellschaft für Schlafmedizin und Schlafforschung (www.schlafmedizin.at) | In German | → Organizations and associations → Austria | 
| ÖGT | Österreichische Gesellschaft für Tuina (www.tuina.or.at) | In German | → Organizations and associations → Pharmacology, toxicology → Austria | 
| ÖGT | Österreichische Gesellschaft der Tierärzte (www.vu-wien.ac.at/oegt/) | In German | → Organizations and associations → Veterinary medicine → Austria | 
| ÖGUM | Österreichische Gesellschaft für Ultraschall in der Medizin (http://oegum.wiemat.at) | In German | → Organizations and associations → Austria | 
| OHF | Occupational Health Facility | In English | → Labour, labour economics | 
| OHSU | Oregon Health and Science University (www.ohsu.edu) | In English | → Higher education, universities → Mathematics and natural sciences → United States | 
| OIE | Office International des Épizooties (www.oie.int) | In French | → Organizations and associations → Veterinary medicine | 
| OIF | Osteogenesis Imperfecta Foundation | In English | → Foundations → Pathology | 
| ÖKG | Österreichische Kardiologische Gesellschaft (www.atcardio.at) | In German | → Organizations and associations → Cardiology → Austria | 
| OLT | Orthotopic Liver Transplantation | In English | → Surgery, orthopaedics, ophthalmology | 
| OMC | Office of Medical Computing | In English | → Computer science | 
| ÖMCCV | Österreichische Morbus Crohn-Colitis ulcerosa Vereinigung (www.oemccv.at) | In German | → Organizations and associations → Pathology → Austria | 
| OMD | Oedème Maculaire Diabétique | In French | → Pathology → Ophthalmology | 
| OMS | Organisation Mondiale de la Santé = MOE, MOS, WHO, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Esperanto | → United Nations | 
| OMS | Organizzazione Mondiale della Sanità = MOE, MOS, WHO, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Italian | → United Nations | 
| OMS | Organización Mundial de la Salú = MOE, MOS, WHO, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Asturian | → United Nations | 
| OMS | Organització Mundial de la Salut = MOE, MOS, WHO, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Catalan | → United Nations | 
| OMS | Organización Mundial de la Salud = MOE, MOS, WHO, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Spanish | → United Nations | 
| OMS | Organisacion mondiâla de la sandât = MOE, MOS, WHO, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Franco-Provençal | → United Nations | 
| OMS | Organización Mundial da Saúde = MOE, MOS, WHO, WGO, СЗО, SZO, MTO, RTD, UMS, PSO, PVO, ÜST (look above) | In Galician | → United Nations | 
| OMSP | Organización Mundial de la Salud Pública | In Spanish | → Organizations and associations → International relations → Public health and hygiene | 
| OMT | Ortopedisen Manuaalisen Terapian | In Finnish | |
| OMT | Osteopathic Manipulative Treatment | In English | |
| OMT | Ortopedisk manuell terapi | In Swedish | → Surgery, orthopaedics, ophthalmology | 
| ONIAM | Office National d'Indemnisation des Accidents Médicaux (www.oniam.fr) | In French | → Central administration → Accidents, risks, safety | 
| ÖNRAP | Österreichisches nationales Radonprojekt | In German | → Austria | 
| ONREK | Office National de Recherche et d'Évaluation en Kinésithérapie | In French | |
| ONS | Opérateur National de Sécurité | In French | → Accidents, risks, safety | 
| OÖGKK | Oberösterreichische Gebietskrankenkassa (www.ooegkk.at) | In German | → Insurance → Austria | 
| OPAS | Organização Pan-Americana da Saúde (www.paho.org) = OPS | Organización Panamericana de la Salud | In Spanish = PAHO | Pan American Health Organization | In English | In Portuguese | → Organizations and associations → International relations |