Africa 
China 
Japan 
MENA 
- Macronucleus
- Macronutrients
- Macroorchidism
- Macrophage activation
- Macrophage activation syndrome
- Macrophage colony stimulating factor
- Macrophage colony-stimulating factor
- Macrophage elastase
- Macrophage inflammatory protein
- Macrophage migration inhibitory factor
- Macrophage polarization
- Macrophage-activating factor
- Macrophages
- Macrophagic myofasciitis
- Macrophomina phaseolina
- Macropinosome
- Macroprolactin
- Macropsia
- Macrosatellite
- Macrosomia
- Macrostomia
- Macrotyloma uniflorum
- Macrovascular disease
- Macula densa
- Macula densa cells
- Macula lutea
- Macular
- Macular corneal dystrophy
- Macular degeneration
- Macular edema
- Macular hole
- Macular scarring
- Macular sparing
- Macular telangiectasia
- Maculopapular rash
- Maculopathy
- Mad2
- MadCAM-1
- Madarosis
- Maddox rod
- Madelung's deformity
- Madhu
- Madin-Darby canine kidney cells
- Madurella
- Madurella mycetomatis
- Mafenide
- Maffucci syndrome
- Magainin
- Maggot therapy
- Magic angle
- Magic angle spinning
- Magic bullets
- Magic number
- Magic syndrome
- Magical thinking
- Magill forceps
- Magnesia
- Magnesium
- Magnesium L-threonate
- Magnesium acetate
- Magnesium bicarbonate
- Magnesium carbonate
- Magnesium chloride
- Magnesium citrate
- Magnesium compounds
- Magnesium glycinate
- Magnesium hydroxide
- Magnesium lactate
- Magnesium orotate
- Magnesium salicylate
- Magnesium silicate
- Magnesium stearate
- Magnesium sulfate
- Magnesium trisilicate
- Magnet therapy
- Magnetic drug delivery
- Magnetic gait
- Magnetic resonance
- Magnetic resonance angiography
- Magnetic resonance cholangiopancreatography
- Magnetic resonance elastography
- Magnetic resonance enterography
- Magnetic resonance microscopy
- Magnetic resonance neurography
- Magnetic resonance spectroscopic imaging
- Magnetic resonance venography
- Magnetic seizure therapy
- Magnetic stirrer
- Magnetic tweezers
- Magnetism
- Magnetization transfer
- Magnetocardiography
- Magnetoencephalography
- Magnetofection
- Magnetometers
- Magnetoreception
- Magnetosomes
- Magnetospirillum
- Magnetotactic bacteria
- Magnetotaxis
- Magnifying glass
- Magnocellular
- Magnocellular cells
- Magnoflorine
- Magnolia officinalis
- Magnolol
- Maintenance dose
- Maintenance of Certification
- Maintenance therapy
- Maisonneuve fracture
- Maitansine
- Major Depression Inventory
- Major Diagnostic Category
- Major adverse cardiovascular events
- Major arterial circle of the iris
- Major basic protein
- Major capsid protein VP1
- Major depressive disorder
- Major depressive episode
- Major duodenal papilla
- Major facilitator superfamily
- Major gene
- Major intrinsic proteins
- Major trauma
- Major vault protein
- Makaton
- Malabsorption
- Malabsorption syndromes
- Malachite green
- Malacia
- Maladaptation
- Maladaptive behavior
- Maladjustment
- Malaise
- Malakoplakia
- Malaoxon
- Malar rash
- Malaria
- Malaria prophylaxis
- Malaria therapy
- Malaria vaccine
- Malassezia
- Malassezia furfur
- Malassezia globosa
- Malassezia sympodialis
- Malate aspartate shuttle
- Malate dehydrogenase
- Malate dehydrogenase 2
- Malate synthase
- Malathion