Africa 
China 
Japan 
MENA 
- Mothballs
- Mother-to-child transmission
- Motherhood
- Motile cilia
- Motilin
- Motilin receptor
- Motion parallax
- Motion perception
- Motion sickness
- Motivated behavior
- Motivated forgetting
- Motivated reasoning
- Motivating operations
- Motivation
- Motivational enhancement therapy
- Motivational interviewing
- Motivational therapy
- Motoneuron
- Motor adaptation
- Motor cognition
- Motor control
- Motor coordination
- Motor cortex
- Motor development
- Motor disorders
- Motor dysfunction
- Motor end plate
- Motor goals
- Motor imagery
- Motor learning
- Motor nerve
- Motor neuron
- Motor neuron disease
- Motor neuron diseases
- Motor neurone disease
- Motor neurons
- Motor neuropathy
- Motor planning
- Motor program
- Motor proteins
- Motor speech disorders
- Motor system
- Motor unit
- Motor unit recruitment
- Mottle
- Moulage
- Mould growth
- Mouse ear swelling test
- Mouse mammary tumor virus
- Mousepox
- Mouth
- Mouth breathing
- Mouth cancer
- Mouth ulcers
- Mouthfeel
- Mouthing
- Mouthparts
- Mouthwash
- Movement assessment
- Movement disorders
- Mowat-Wilson syndrome
- Moxetumomab pasudotox
- Moxibustion
- Moxidectin
- Moxifloxacin
- Moxonidine
- Moyamoya disease
- Mozart effect
- Mu rhythm
- Mucicarmine stain
- Mucilage
- Mucin
- Mucin-1
- Mucinosis
- Mucinous adenocarcinoma
- Mucinous carcinoma
- Mucinous carcinoma of the breast
- Mucinous cystadenoma
- Mucinous cystic neoplasm
- Mucins
- Muckle-Wells syndrome
- Mucoadhesion
- Mucocele
- Mucociliary clearance
- Mucocutaneous junction
- Mucoepidermoid carcinoma
- Mucogingival junction
- Mucolipidoses
- Mucolipidosis
- Mucolipidosis type IV
- Mucolytic agent
- Muconic acid
- Mucoperiosteum
- Mucopolysaccharidosis
- Mucopolysaccharidosis type I
- Mucoprotective
- Mucoprotein
- Mucopurulent discharge
- Mucor
- Mucormycosis
- Mucosa
- Mucosa-associated lymphoid tissue
- Mucosal immunity
- Mucosal immunology
- Mucosal melanoma
- Mucosal surfaces
- Mucosal tissue
- Mucosal-associated invariant T cells
- Mucosectomy
- Mucositis
- Mucous cell
- Mucous glands
- Mucous membrane
- Mucous membrane pemphigoid
- Mucuna
- Mucuna pruriens
- Mucunain
- Mucus
- Mudras
- Muehrcke's nails
- Mueller-Hinton agar
- Muenke syndrome
- Mugwort
- Muir-Torre syndrome
- Mulder's sign
- Mullerian agenesis
- Mullerian anomalies
- Multi-component reactions
- Multiangle light scattering
- Multicellular organisms
- Multicenter AIDS Cohort Study
- Multicenter Automatic Defibrillator Implantation Trial
- Multicenter trial
- Multicentric reticulohistiocytosis
- Multichannel analyzer
- Multicystic dysplastic kidney
- Multidetector computed tomography
- Multidrug resistance
- Multidrug resistance-associated protein 2
- Multidrug resistant tuberculosis
- Multidrug-resistant bacteria
- Multienzyme complex
- Multifactor dimensionality reduction
- Multifactorial inheritance
- Multifidus
- Multifidus muscle
- Multifocal atrial tachycardia
- Multifocal choroiditis and panuveitis
- Multifocal fibrosclerosis
- Multifocal intraocular lens