- MAC
- Macroglobulinemia, Waldenstrom's
- Macroglossia
- Macular degeneration, age-related
- Mad cow disease
- Maduromycosis
- Magnesium, decreased serum
- Magnesium, increased serum
- Magnesium salicylate
- Major depression
- Malabsorption
- Malaria
- Malassezia furfur
- Male hypogonadism
- Male infertility
- Malignancy
- Malignant hypertension
- Malignant melanoma
- Malignant teratomas
- Malingering
- Mallory-Weiss syndrome
- Malnutrition
- Malnutrition, in elderly
- Mania
- Manic depression
- Maple bark stripper's disease
- Maprotiline
- Marfan's syndrome
- Masochism, sexual
- Mass
- Mast cell stabilizers, topical ophthalmic
- Mastitis
- Maternal hypothyroidism
- Mavik
- Maxair
- Maxzide
- MDMA (methylenedioxymethamphetamine)
- Measles
- Mechlorethamine
- Meclofenamate sodium
- Meclomen
- Medial epicondylitis
- Medial meniscus tears
- Mediastinal mass
- Medicare coverage requirements, for home oxygen therapy
- Medroxyprogesterone
- Medrysone 1% suspension
- Medullary thyroid carcinoma (MTC)
- Medulloblastoma
- Mefenamic acid
- Megacolon
- Megestrol acetate
- Meglitinide analogs
- Melanoma
- Melena
- Melioidosis
- Mellaril
- Melphalan
- Membranoproliferative glomerulonephritis
- Membranous nephropathy
- Memory loss
- MEN 1
- MEN 2
- Meniere's syndrome
- Meningiomas
- Meningiomas, of spinal cord
- Meningitis
- Meningococcal meningitis
- Meningococcus, drugs for
- Meningoencephalitis
- Meniscus tears, medial
- Menopausal syndrome
- Menopause
- Menorrhagia
- Menstruation, painful
- Mental retardation, fragile X
- Mentax
- Menthol/camphor
- Meperidine
- Meralgia paresthetica
- Mercaptopurine
- Mercury poisoning
- Mesenteric ischemia
- Mesenteric vein occlusion
- Mesna
- Mesoridazine
- Mesothelioma
- Mesothelioma, peritoneal
- Metabolic acidosis
- Metabolic alkalosis
- Metabolic alkalosis, and compensation for
- Metabolic disturbances, etiology of delirium
- Metastases
- Metformin
- Methadone
- Methanol poisoning
- Methcathinone
- Methemoglobinemia
- Methicillin-resistant staphylococcus, drugs for
- Methotrexate
- Methotrexate, in breast-feeding women
- Methyldopa
- Methylenedioxymethamphetamine (MDMA)
- Methylprednisolone
- Methysergide, for migraine
- Metipranolol HCl 0.3% solution
- Metoclopramide
- Metolazone
- Metoprolol
- Metronidazole
- Mevacor
- Mexiletine
- Micardis
- Micardis HCT
- Miconazole
- Microalbuminuria
- Microangiopathic hemolytic anemia
- Microbial pathogens
- Microinvasive carcinoma, cervical
- Micronase
- Microscopic colitis
- Microscopic polyangiitis
- Microsporidia, chronic diarrhea from
- Midazolam
- Midcycle spotting
- Middle ear
- Miglitol
- Migraine
- Miliaria
- Mineral seal oil poisoning
- Minimal change disease
- Minipress
- Minoxidil
- Miotics, topical
- Mirtazapine
- Mites
- Mithramycin
- Mitomycin
- Mitotane
- Mitoxantrone
- Mitral regurgitation
- Mitral stenosis
- Mitral valve prolapse
- Mixed Connective Tissue Disease
- Mixed connective tissue disease (MCTD)
- Mixed papillary carcinoma, of thyroid
- Moban
- Modified Child-Pugh classification, for cirrhosis
- Moduretic
- Moexipril
- Mole, atypical
- Mole, hydatidiform
- Molindone
- Molluscum contagiosum
- Mometasone furoate
- Monge's disease
- Monoamine oxidase (MAO) inhibitors
- Mononeuropathies
- Mononucleosis
- Monopril
- Montelukast
- Moraxella catarrhalis
- Moraxella catarrhalis pneumonia
- Morbilliform lesions
- Moricizine
- Morning sickness
- Morphine
- Morphine, addiction to
- Mosquito bites
- Motility disorders
- Motor neuron disease
- Motor oil poisoning
- Motor tics
- Motrin
- Mountain sickness
- Movement disorders
- MS Contin
- Mucocutaneous candidiasis
- Mucocutaneous leishmaniasis
- Mucor
- Mucormycosis
- Multilocular hydatid disease
- Multinodular goiter
- Multiple endocrine neoplasia, type 1 (MEN 1)
- Multiple Endocrine Neoplasia, type 2 (MEN 2)
- Multiple myeloma
- Multiple myeloma, paraneoplastic syndromes with
- Multiple myeloma, systemic agents
- Multiple sclerosis
- Mumps
- Munchausen by proxy
- Munchausen syndrome
- Mupirocin, for impetigo
- Murmur, diastolic
- Murmur, systolic
- Muscarinic mushroom poisoning
- Muscle cramps
- Muscular dystrophies
- Mushroom picker's disease
- Mushroom poisoning
- Myasthenia gravis
- Myasthenic syndrome
- Mycetoma
- Mycobacterial lymphadenitis
- Mycobacterial pulmonary infections, nontuberculous
- Mycobacterium, atypical infection with
- Mycobacterium abscessus, in pulmonary infections
- Mycobacterium avium complex (MAC)
- Mycobacterium avium-intracellulare, in chronic diarrhea
- Mycobacterium bovis, intestinal infection with
- Mycobacterium chelonei, in skin and soft tissue infections
- Mycobacterium fortuitum, in skin and soft tissue infections
- Mycobacterium fortuitum-cheilonei, drugs for
- Mycobacterium infection, atypical
- Mycobacterium kansasii
- Mycobacterium leprae
- Mycobacterium malmoense, in pulmonary infections
- Mycobacterium marinum, in skin and soft tissue infections
- Mycobacterium scrofulaceum, in childhood lymphadenitis
- Mycobacterium tuberculosis
- Mycobacterium xenopi, in pulmonary infections
- Mycoplasma, drugs for
- Mycoplasma pneumoniae pneumonia
- Mycosis fungoides
- Mycotic aneurysms, drug use and
- Mycotic infections
- Myelocytic leukemia, treatment for
- Myelodysplastic syndromes
- Myelofibrosis
- Myeloma, multiple
- Myelomonocytic leukemia, acute, treatment for
- Myeloproliferative disease, paraneoplastic syndromes with
- Mykrox
- Mylotarg
- Myocardial hypertrophy
- Myocardial infarction, acute
- Myocardial infarction, acute, thrombolytic therapy for
- Myocardial infarction (MI), acute
- Myocardial infarction (MI), acute, thrombolytic therapy for
- Myocardial ischemia
- Myocarditis
- Myoclonic seizures
- Myoclonic seizures, drug treatment for
- Myoclonus
- Myoclonus, nocturnal
- Myopathy(ies)
- Myositis
- Myotonic dystrophy
- Myxedema