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Medical Dictionary: m

Word	Definition
m	meter
MA	mental age
maceration	Softening of a solid by soaking in a liquid.
macro-	large
macrocephaly	Abnormally large head.
macrocheilia	Abnormally large lips.
macrodactyly	Abnormally large fingers or toes.
macrodontia	Abnormally large teeth.
macroglossia	Enlargement of the tongue, which may be congenital or may develop as a result of a tumor or edema, or in association with hyperpituitarism.
macrognathia	Abnormally large jaw.
macromelia	Abnormally large arms or legs.
macrophage	A type of white blood cell that is part of the immune system. It digests targeted cells and cellular debris.
macrostomia	Abnormally large mouth.
macul/o	spot
macula lutea	An oval, yellow spot in the retina, 3 to 5 mm in diameter It is devoid of retinal blood vessels, except in its periphery.
macular	Denoting the central retina.
macular degeneration	Degenerative changes in the retina usually of older adults which results in a loss of vision in the center of the visual field.
macule	Small flat skin spots on the skin.
maculopathy	Any pathologic condition of the macula lutea.
madarosis	Loss or underdevelopment of eyelashes or eyebrows.
maggot	Larva of a fly.
magnetic resonance imaging	Non-invasive method of imaging internal anatomy a strong magnetic field and pulses of radiofrequency energy. Effective for imaging soft tissue, organs and joints.
mal-	bad, deficient
malabsorption	Inadequate intestinal absorption of nutrients.
-malacia	softening
malaise	A general feeling of illness or discomfort or feeling unhealthy.
malaria	A serious parasitic disease caused by mosquito bites. Symptoms include chills, flu-like symptoms, fever, vomiting, diarrhea, and jaundice.
malformation	An abnormal physical structure in the body.
malignant melanoma	The most dangerous form of skin cancer. Melanomas are usually brown or black, but can appear pink, tan, or even white.
malingering	Faking symptoms for personal gain or attention.
malleolus	The bony prominence on either side of the ankle.
malleus	The largest and outermost of the three ossicles of the ear. Also called hammer.
malnutrition	A condition caused by insufficient intake of nutrients.
malocclusion	Faulty contact between the upper and lower teeth when the jaw is closed.
malpractice	Failure to render proper professional services through reprehensible ignorance or negligence especially when injury occurs.
malunion	Faulty alignment of broken bone fragments.
mamm-	breast
mamm/o	breast
mammary gland	Milk producing gland.
mammography	Radiographic examination of the breast.
mammoplasty	Plastic surgery of the breasts.
mandible	The large, u-shaped bone that supports the lower teeth, forming the lower jaw.
mandibul/o	mandible (lower jaw bone)
mania	An abnormally excessive elated, enthusiastic mental state.
-mania	obsession with
manometer	A device for measuring gas or liquid pressure.
manubrium	The uppermost part of the sternum.
MAP	mean arterial pressure
marsupialization	A surgical procedure for treating cysts. The cyst is widely opened creating a pouch.
-masesis	chewing, mastication
masseter muscle	The thick rectangular muscle in the cheek that functions to close the jaw.
mast/o	breast
mastalgia	Breast pain.
mastectomy	Surgical procedure to remove one or both breasts.
mastication	The process of chewing and grinding food in the mouth.
mastocytoma	A solid tumor consisting of a dense infiltration of mast cells.
mastocytosis	Disorders characterized by the abnormal increase of mast cells in organs and tissues.
mastodynia	Pain in the breast.
mastoid	Breast-shaped.
mastoid/o	rounded protrusion of bone behind the ear
mastoidectomy	Surgical removal of mastoid air cells in the hollow, air-filled spaces in the skull behind the ear.
mastoiditis	Inflammation of the mastoid air cells It is usually a complication of otitis media.
mastopexy	Breast lift surgery.
masturbation	Sexual self-gratification.
maxill/o	upper jawbone formed from the fusion of two maxillary bones
maxilla	One of a pair of irregularly shaped bones that form the upper jaw.
maxillofacial	Pertaining to the jaws and face.
MBC	maximum breathing capacity
MBD	minimal brain dysfunction
mc	mCi millicurie
mcg	microgram
MCH	mean corpuscular hemoglobin
MCV	mean corpuscular volume
MD	muscular dystrophy
MDI	metered-dose inhaler
measles	An acute, contagious viral disease characterized by eruption of red spots on the skin, fever, and catarrhal symptoms. Usually occurs in childhood.
meat/o	a natural opening
meatus	An opening or passage.
medi/o	middle
medial	Toward the body's midline
median nerve	A major nerve of the arm, suppling sensory and motor innervation to parts of the forearm and hand.
mediastinal	Pertaining to a median septum or space between two parts of the body.
mediastinitis	Inflammation of the mediastinum.
mediastinum	The central section of the chest cavity, containing the heart, arteries, veins, esophagus, trachea, bronchi, lymph nodes and thymus.
medicare	Federal program that provides health insurance benefits to persons over the age of 65 and others eligible for Social Security benefits. It consists of hospital insurance (Part A) and supplementary medical insurance (Part B).
meditation	A state of focusing on a single thing, eliminating influences of external stimuli.
meds	medications
medull/o	medulla, marrow
medulla	The inner region of an organ or body structure.
medulla oblongata	The lower portion of the brain stem. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.
medulloblastoma	A malignant neoplasm that may be classified either as a glioma or as a primitive neuroectodermal tumor of childhood.
mega-	large, great
megacolon	Extreme dilatation of the colon.
megaloblastic anemia	A blood disorder in which the number of red blood cells is too low due to abnormally large red blood cell size. Can also be called vitamin B-12 or folate deficiency anemia.
megaloblasts	Red blood cell precursors that are abnormally large and dysfunctional. Found in patients with pernicious anemia.
megalomania	Delusions of grandeur or exaggerated personal importance, wealth or power.
-megaly	enlargement
meibomian glands	The small sebaceous glands located on the inner surface of the eyelids between the tarsal plates and conjunctiva.
meiosis	A type of cell division in which a nucleus divides into four daughter nuclei
mel/o	limb
melan/o	black, dark
melanoma	A malignant, rapidly growing neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites.
melanosis	Disorders of increased melanin pigmentation that develop without preceding inflammatory disease.
melatonin	A hormone produced by the pineal gland. It plays a role in the regulation of sleep, mood, and reproduction.
melena	The black, tarry, foul-smelling feces that contain degraded blood.
meli-	honey, sugar
membrane	Thin layers of tissue which covers parts of the body, separates adjacent cavities, or connects adjacent structures.
memory	The mental functions of learning, retention, recall and recognition.
men/o	menstruation, menses
menarche	The first menstrual period.
mening/o	membranes
meninges	The three membranes that envelop the brain and the spinal cord.
meningioma	A relatively common neoplasm of the central nervous system.
meningitis	An acute inflammation of the protective membranes covering the brain and spinal cord. May be viral or bacterial.
meningocele	Surgery to repair birth defects of the spine and spinal membranes.
meniscus	Crescent-shaped cartilage inside the knee joint that absorb shock and stabilize the joint.
menopause	The permanent cessation of menstruation.
menorrhagia	Excessive uterine bleeding during menstruation.
menses	Blood and tissue discharged from the uterus periodically.
menstrual cycle	The period from onset of one menstrual bleeding to the next in an ovulating female. The menstrual cycle is regulated by endocrine interactions of the hypothalamus; the pituitary gland; the ovaries; and the genital tract.
menstruation	The (approximately) monthly discharge of blood and cellular debris from the uterus by nonpregnant women, occurring from puberty to menopause.
ment/o	mind
menthol	An alcohol produced from mint oils or prepared synthetically.
MEP	maximal expiratory pressure
mEq	milliequivalent
mEq/L	milliequivalent per liter
-mer	smallest unit of a repeating structure, member of a particular group
mer/o	part, partial
merkel cells	Modified epidermal cells located in the stratum basale (the innermost layer of the epidermis). They are found mostly in areas where sensory perception is acute, such as the fingertips.
mes-	middle, mean
mesenteric	Relating to the double layer of peritoneum suspending the intestine from the posterior abdominal wall.
mesentery	A double layer of peritoneum that encloses the intestines and attaches them to the posterior abdominal wall.
meso-	middle
mesomorphic	Having a robust, muscular body build.
meta-	beyond, change
metabolism	The chemical reactions that occur within the cells, tissues or an organism.
metacarpals	The long bones in the hand located between the phalanges of the fingers and the carpal bones of the wrist.
metagenome	A collective genome representative of the many organisms, primarily microorganisms, existing in a community.
metastasectomy	Surgery to remove one or more neoplasm metastases.
metastasis	The spread of a cancer or other disease from one body part to another not directly connected with it.
metatarsal bones	The five long bones of the metatarsus, articulating with the tarsal bones proximally and the phalanges of toes distally.
metatarsalgia	Pain in the region of the metatarsus.
metatarsals	Five long bones in the foot, located between the ankle and toes.
metatarsus	The part of the foot between the tarsus and the toes.
-meter	measurement, instrument to measure
methenamine	An antibacterial compound most commonly used in the treatment of urinary tract infections.
method/o	procedure, technique
metr/o	uterus (womb)
metritis	Inflammation of the uterus.
metrorrhagia	Abnormal uterine bleeding that is not related to menstruation.
-metry	to measure
Mg	magnesium
MHC	mental health care
MI	myocardial infarction
micro-	small
microbial	Relating to microbes.
microbiology	The study of microorganisms.
microbiota	The full collection of microbes (bacteria, fungi, virus, etc.) that naturally exist within a specific environment.
microcephaly	Abnormal smallness of the head; a congenital abnormality
microcheilia	Abnormally small lips.
micrococcus	A genus of gram-positive, spherical bacteria found in soils and fresh water, and frequently on the skin of man and other animals.
microdontia	Abnormally small teeth.
microglia	A type of non-nervous tissue found in the central nervous system, that acts as a phagocyte at sites of neural damage or inflammation.
micrognathism	Abnormally small jaw.
microstomia	A congenital defect of an abnormally small mouth.
microsurgery	Surgical procedures using microscope.
microtia	A congenital deformity of the external ear.
microvessels	The finer blood vessels of the vasculature that are generally less than 100 microns in internal diameter.
midwifery	The practice of assisting women in childbirth.
migraine	Moderate to severe, painful headache that may occur with symptoms like nausea, vomiting, fatigue and numbness.
milli-	one thousandth
-mimesis	imitation, simulation
mindfulness	A psychological state of awareness.
mio-	smaller
miosis	Excessive pupillary constriction.
miotics	Drugs causing contraction of the pupil.
MIP	maximal inspiratory pressure
mis/o	opposite, aversion
miscarriage	Common term for the loss of an embryo or fetus before the 20th week of pregnancy.. This term is longer accepted in clinical usage.
mites	They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans , producing various irritations of the skin.
mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of eukaryotic cells.
mitral valve	The valve between the left atrium and left ventricle of the heart.
mitral valve prolapse	Abnormal protrusion of mitral valve leaflets in the left atria during systole. Results in blood backflow, which causes systolic murmurs, arrhythmia and mitral valve insufficiency.
mitral valve stenosis	Narrowing of the passage through the mitral value. Caused by fibrosis and calcinosis. Rheumatic fever is a primary cause.
ml	milliliter
MLD	minimum lethal dose
mm	millimeter
mmHg	millimeter of mercury
mMol	millimole
Mn	manganese
-mnesia	memory
modality	A factor that makes a patient's symptoms better or worse.
mogi-	difficult
mol	molecular weight
molar	The most posterior teeth on either side of the jaw which are used for grinding.
mon/o	single, one
MONO	monocyte
monocytes	Large, phagocytic mononuclear leukocytes. Monocytes help other white blood cells remove dead or damaged tissues, attack cancer cells and regulate immunity response. Produced in the bone marrow
monorchism	Absence of one testis.
monosomy	The existence in a cell of only one instead of the normal diploid pair of a particular chromosome.
morals	Standards of conduct that distinguish right from wrong.
morbid	Diseased or abnormal.
morbid obesity	The condition of weighing two or more times the ideal weight. In the body mass index, morbid obesity is defined as having a BMI greater than 40.0 kg/m2.
morbidity	The relative incidence of a particular disease
morph/o	shape, form
morphine	The principal alkaloid in opium and the prototype opiate analgesic and narcotic.
mort/o	death
mortality	The relative frequency of deaths in a specific population.
morula	An early embryo that is a compact mass.
mot-	move
-motor	motion
MRA	magnetic resonance angiography
MRI	magnetic resonance imaging
MRSA	methicillin resistant staph aureus
MS	multiple sclerosis
MS (2)	mitral stenosis
MSH	melanocyte stimulating hormone
muc/o	mucus
mucolipidoses	A group of inherited metabolic diseases in which mucopolysaccharides and lipids accumulate in tissues
mucositis	An inflammation of a mucous membrane, such as the lining of the mouth and throat.
mucous membrane	The moist lining of body cavities and hollow organs such as the mouth, the nose, the eyelids, the intestine and the vagina.
mucus	The viscous secretion of mucous membranes. It contains mucin, white blood cells, water, inorganic salts, and exfoliated cells.
multi	many, much
multiple sclerosis	An immune-mediated process in which the immune system attacks the myelin sheath that surrounds nerve fibers.
mumps	An acute viral infection characterized by swelling of the salivary glands, especially the parotids. Usually seen in children.
muscul/o	muscle
muscular dystrophies	A heterogeneous group of inherited myopathies, characterized by wasting and weakness of the skeletal muscle.
muscular dystrophy	A group of over thirty genetic diseases characterized by progressive degeneration of the skeletal muscles that control movement.
mutation	Any detectable and heritable change in the genetic material that causes a change in the genotype and which is transmitted to daughter cells and to succeeding generations.
MV	mitral valve
MVA	motor vehicle accident
MVP	mitral valve prolapse
MVV	maximal voluntary ventilation
My	myopia
my/o	muscle
myalgia	Muscle pain.
myasthenia gravis	A chronic autoimmune disease characterized by weakness of the skeletal muscles.
myc/o	fungus
mycetoma	A chronic progressive subcutaneous bacterial or fungal infection.
mycology	The study of fungi and fungus diseases.
mycosis	A fungal inflection.
mydriasis	Abnormal dilation of the pupil.
myel/o	spinal cord, bone marrow
myelin	A white fatty material that encloses certain axons and nerve fibers acting as an electrical insulator.
myelitis	An inflammation of the spinal cord.
myelodysplastic syndromes	A group of cancers in which immature blood cells in the bone marrow fail to mature and become healthy.
myelography	A procedure that uses dye with x-rays or CT scans to assess the spinal cord,
myiasis	The invasion of living tissues by dipterous larvae.
myocardi/o	myocardium (heart muscle)
myocardial infarction	Partial death of heart tissue caused by an obstructed blood supply. Commonly called "heart attack".
myocardial ischemia	A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart.
myocarditis	Inflammation of the heart muscle. Caused by a wide range of infections and other problems.
myocardium	The heart muscle. Its contractions pump blood from heart to the lungs and systemic circulatory system.
myocele	Protrusion of muscle substance through a hole in its sheath
myoclonus	Sudden, involuntary jerking of a muscle.
myofascial release	Physical therapy used to treat chronic pain in the tissues that surround and support muscles.
myogenic	Originating in the muscles.
myolysis	Breakdown of muscle tissue.
myoma	A benign neoplasm of the muscles.
myometrium	The smooth muscle coat of the uterus, which forms the main mass of the organ.
myoparesis	Slight muscle paralysis.
myopia	Nearsightedness. A condition where close objects appear clearly, but distant objects appear blurry.
myorrhaphy	Suture of muscle tissue or a muscle wound.
myosarcoma	A general term for a malignant neoplasm derived from muscular tissue.
myositis	Inflammation of a muscle or muscle tissue.
myotonia	Tonic muscle spasm or muscular rigidity.
myotonic	Pertaining to muscle tone.
myring/o	tympanic membrane (eardrum)
myringitis	Inflammation of the eardrum.
myringotomy	Surgical incision in the eardrum to relieve fluid pressure.
myx/o	mucus
myxoma	A benign neoplasm derived from connective tissue.