Medical dictionary

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Macroglobulinaemia: in certain conditions, such aswaldenstrom's macroglobulinaemia, affected lymphocytes produce an excess amount of an abnormal antibody known as IgM for macroglobulin.
Macrophage: a type ofwhite blood cell which migrates from the blood into tissues and acts as a scavenger, ingesting particles such as bacteria.
Macula: the pigmented central area or "yellow spot" of the retina that is adjacent to the optic nerve. It is the most sensitive area of the retina and contains the fovea, a depressed region that is responsible for detailed central vision.
Macule: small: flat spot.
Maculopapular: small spot-related rash.
Magnetic resonance imaging (MRI): a body scanning technique which uses an intense magnetic field to generate images of the internal organs.
Malabsorption: inability of the gastrointestinal tract to absorb food, drugs or any substance needed to maintain good health; if not countered leads to weight loss.
Malaise: vague illness.
Malar rash: fixed red rash over the cheeks.
Malignancy: a term applied to tumours characterised by the uncontrolled proliferation of cells. See alsocancer.
Malignant: severe, progressive, and unresponsive to treatment.
Malnutrition: a condition caused by not eating enough food or not eating a balanced diet.
Mammary: related to the breast.
Mammoplasty: plastic surgery to the breast.
Mastectomy: amputation of the breast.
Manifestation: the outward sign that an illness is present - a symptom or condition.
Manifesting carrier: a female carrier of an X-linked condition who shows symptoms.
Marfan syndrome: an inherited disorder of connective tissue which affects many organ systems, including the skeleton, lungs, eyes, heart and blood vessels. Further info.
Marma massage: as part of ayurvedic medicine, marma points are defined as areas where muscles, vein, arteries, bones and joints meet. Stimulation promotes physical and mental rehabilitation.
Mast cell: the mast cell is related to themonocyte/macrophage cells of the immune system and is found in most tissues.
Mast cell leukaemia: excessive production of mast cells may be seen in the conditions systemic mastocytosis and mast cellleukaemia.
Mastalgia: breast pain. Further info.
Masticatory: chewing-related.
Mastitis: sore breasts.
Mastocyte: connective tissue cell.
Mastodynia: breat pain.
Maternal: coming from the mother.
Maxillary: face bone-related.
Meatus: an opening in a bone or organ.
Meckel's Diverticulum: a birth defect in which a small sac forms in the ileum.
Meconium: the dark, greenish stools passed by a newborn baby.
Medial epicondylitis: 'medial' meaning on the inner side of the elbow. This condition is characterised by pain and tenderness.
Meditation: ancient Eastern technique, similar to self-hypnosis, in that it relaxes the mind and the body.
Medulla: the inner portion of an organ.
Megacolon: swollen colon usually caused by severe constipation.
Megakaryocyte: large cell in thebone marrow which produceplatelets.
Melaena: passage of dark coloured, tarry stools, due to the presence of blood altered by the intestinal juices.
Melanin: the color, or pigmentation, of the skin.
Melanoma: a malignant skin tumor that involves the skin cells that produce pigment (melanin).
Melatonin: a human hormone that is derived fromserotonin, is secreted by the pineal gland especially in response to darkness, and has been linked to the regulation of circadian rhythms.
Membrane: a thin layer or sheet of tissue.
Menarche: the establishment of the menstrual function, the time of the first menstrual period flow.
Meniere's Syndrome: the collection of fluctuating symptoms: tinnitus, hearing loss, and vertigo. Further info.
Meninges: the three membranes that surround and protect the brain and spinal cord.
Meningitis: inflammation of the meninges, the membranes that envelope the brain and spinal cord. It may be caused by a bacterium, fungus or virus. Further info.
Meniscus: free rings of cartilage, like washers, lying between the cartilage- covered bones in the knee, acting as extra shock absorbers; each knee has an inside (medial) and outside (lateral) meniscus; these cartilages often get damaged in sport.
Menorrhagia: heavy or painful periods.Further info.
Menopause: the point when menstruation stops permanently.
Mesentary: peritoneal tissue that attaches the gut to the wall of the abdominal cavity.
Meta-analysis: a method of summarizing previous research by reviewing and combining results from multiple clinical trials. Meta-analyses are attempted when previous studies were too small individually to achieve meaningful or statistically significant results.
Metabolism: all the complex chemical processes within the human body necessary to maintain life.
Metastasis: the process by which tumor cells multiply and spread.
Metered-dose inhaler (MDI): a device that dispenses a specific amount of medication in a form suitable for inhaling.
MI: myocardial infarction.
Microbe: a microscopic living organism, such as a bacteria, fungus, protozoa or virus.
Micturition: urination.
Migraine: recurrent, intense, throbbing headache, usually on one side of the head and often associated with sickness and visual disturbances.Further info.
Milium: whitehead, a small subepidermal keratin cyst.
Minimal access surgery (mas): another term for keyhole surgery.
Minimal invasive therapy (mit): another term for keyhole surgery.
Miscarriage: loss of the fetus during pregnancy.
Mitochondria: a rod-shaped or oval body in cells that is the site of energy production by means of oxidation.
Mitosis: the process of cell division.
Mixed connective tissue disease(MCTD): types ofautoimmune diseases also known as 'overlap syndromes'.
Molluscum contagiosum: a skin condition caused by a pox virus infection, distinguished by small dome-shaped papules (bumps) on the face, upper trunk or extremities. Further info.
Monoarthritis: arthritis affecting only one joint.
Monoclonal: proteins made by cells which all belong to the same clone are identical and are called monoclonal.
Monoclonal antibodies: antibodies artificially produced in tissue culture which may be tailor-made to combat disease.
Monocyte: a type ofwhite blood cell of relatively large size which acts as a scavenger and ingests large particles.
Monocytic leukaemia: cancer of the blood due to proliferation of cells of the monocyte series.
Monosomy: term which indicates the loss of a wholechromosome.
Motility: the movement of food through the gut.
Motor: the term used to describe things that cause movement, such as a muscle or nerve.
Motor Neurone Disease (MND): a group of diseases in which the nerve cells controlling the muscles that enable us to move around, speak, breathe and swallow fail to work normally. Further info.
Mucositis: inflammation of the mouth and throat.
Mucous membrane: the moist layer of tissue lining the digestive, respiratory, urinary and reproductive tracts -- all the body cavities with openings to the outside world except the ears.
Mucus: a thick liquid that moistens and lubricates body tissues, including those in the airways and lungs. ("Mucous" is the adjective form.)
Multiple myeloma: acancer caused by uncontrolled proliferation of the white blood cells called plasma cells within thebone marrow. The malignant cells do not usually accumulate in the blood and the tumour growth is restricted to the bones. This leads to bone destruction and is often associated with kidney problems.
Multiple sclerosis: a chronic, often disabling disease of the central nervous system.
Mumps: a viral infection which causes swelling of the salivary glands.
Muscle: tissue composed primarily of contractile cells that effects movement in the body.
Muscular dystrophy: a group of degenerative muscle diseases characterized by gradual weakening and deterioration of skeletal muscles, and sometimes the heart and respiratory muscles. Further info.
Musculoskeletal system: comprises bones, muscles, joints and the associated periarticular tissues (peri=around; articular=of or relating to the joints).
Mutation: a minute genetic change to DNA, for example by exposure to hazardous chemicals or copying errors during cell division. If these affect normal cell function it can lead to disease development.
Myalgia: pain in one or more muscles.
Mycobacterium: a group of bacteria with many disease-causing members. The causative agents for tuberculosis, leprosy and MAC all belong to this group.
Mycoplasma: a group of bacteria, some of whose members cause disease in animals and humans. Mycoplasma are very simple one-celled organisms without an outer membrane. They penetrate and infect individual cells. Most commonly, mycoplasma cause pneumonia.
Mycosis: any disease caused by a fungus.
Myelin: fatty material, composed of lipid and protein, that forms a protective sheath around nerve fibres.
Myelitis: inflammation of either the spinal cord or the bone marrow.
Myeloblastic: immature cells of the myeloid series.
Myelodysplasia or myelodysplastic syndromes (MDS): a group of closely linked conditions in which the process of blood cell formation is disturbed by a failure of the immature cells to grow and develop normally. Sometimes referred to as "preleukaemia", although only a minority of patients will ever developleukaemia.
Myelofibrosis: a disease in which thebone marrow is taken over by fibrous tissue and is no longer able to: produce adequate numbers of mature blood cells. Often accompanied by enlargement of thespleen.
Myeloid: collective term for the non-lymphocyte groups of white blood cells. It includes cells from the granulocyte,monocyte and platelet lineages. .
Myeloma: see multiple myeloma.
Myelomonocytic: a condition which affects both the myeloid and monocytic cells.
Myelopathy: any disease affecting the spinal cord.
Myelopoiesis: the process of production and maturation ofmyeloid cells. See alsohaematopoiesis.
Myeloproliferative disorders: a group of disorders characterised by the over- production of blood cells by the bone marrow. One or more of the cell lineages may be involved and treatment varies according to the type and severity of the disease. See alsoessential thrombocythaemia, polycythaemia rubra vera.
Myelosclerosis: see myelofibrosis.
Myelotoxic: destructive to bone marrow.
Myocardial: refers to the heart's muscle mass.
Myocardial infarction: a heart attack.
Myocardium: the heart muscle.
Myocyte: a muscle cell.
Myoglobin: the oxygen-carrying pigment in muscle.
Myopathy: progressive muscle weakness.
Myopia: nearsightedness.
Myosin: a muscle protein found in the myofibril that is active in muscle contraction.
Myositis: inflammation of the muscle. See also polymyositis.
Myotonic dystrophy: gets its name from "myotonia", which means muscle stiffness. It is usually progressive although symptoms can appear at any time, from birth to old age.
Myringotomy: draining fluid from within the eardrum by needle.

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