(A1-5, A7-10, A13, A14, A17, B2) AB, abnorm
Used with organs for congenital defects producing changes in the morphology of the organ. It is used also for abnormalities in animals.
administration & dosage
(D1-3, D3-27) AD, admin
Used with drugs for dosage forms, routes of administration, frequency and duration of administration, quantity of medication, and the effects of these factors.
(B6, D, E1, E3, E4, E6, E7, J2) AE, adv eff
Used with drugs, chemicals, or biological agents in accepted dosage - or with physical agents or manufactured products in normal usage - when intended for diagnostic, therapeutic, prophylactic, or anesthetic purposes. It is used also for adverse effects or complications of diagnostic, therapeutic, prophylactic, anesthetic, surgical, or other procedures, but excludes contraindications for which "contraindications" is used.
(D1-7, D9-17, D19-23) AG, agon
Used with chemicals, drugs, and endogenous substances to indicate substances or agents that have affinity for a receptor and intrinsic activity at that receptor. (From Textbook of Pharmacology, 1991, p.16)
analogs & derivatives
(D3) AA, analogs
Used with drugs and chemicals for substances that share the same parent molecule or have similar electronic structure but differ by the addition or substitution of other atoms or molecules. It is used when the specific chemical heading is not available and no appropriate group heading exists.
(D) AN, anal
Used for the identification or quantitative determination of a substance or its constituents and metabolites; includes the analysis of air, water, or other environmental carrier. It excludes the chemical analysis of tissues, tumors, body fluids, organisms, and plants for which "chemistry" is used. The concept applies to both methodology and results. For analysis of substances in blood, cerebrospinal fluid, and urine the specific subheading designating the fluid is used.
anatomy & histology
(A1-5, A7-10, A13, A14, A17, B2, B6) AH, anat
Used with organs, regions, and tissues for normal descriptive anatomy and histology, and for the normal anatomy and structure of animals and plants.
antagonists & inhibitors
(D1-17, D19-23) AI, antag
Used with chemicals, drugs, and endogenous substances to indicate substances or agents which counteract their biological effects by any mechanism.
(D6, D8, D9, D11-13, D17, D24) BI, biosyn
Used for the anabolic formation of chemical substances in organisms, in living cells, or by subcellular fractions.
(B2, C, D1-24, D27, F3) BL, blood
Used for the presence or analysis of substances in the blood; also for examination of, or changes in, the blood in disease states. It excludes serodiagnosis, for which the subheading "diagnosis" is used, and serology, for which "immunology" is used.
(A1-5, A8-10, A13, A14, A17, C4) BS, blood supply
Used for arterial, capillary, and venous systems of an organ or region whenever the specific heading for the vessel does not exist. It includes blood flow through the organ.
(B2, C, D1-24, D27, F3) CF, csf
Used for the presence or analysis of substances in the cerebrospinal fluid; also for examination of or changes in cerebrospinal fluid in disease states.
(D2-23, D25-27) CS, chem syn
Used for the chemical preparation of molecules in vitro. For the formation of chemical substances in organisms, living cells, or subcellular fractions, "biosynthesis" is used.
(C1-20, C22, C23, F3) CI, chem ind
Used for biological phenomena, diseases, syndromes, congenital abnormalities, or symptoms caused by endogenous or exogenous substances.
(A2-17, B1, B3-7, C4, D) CH, chem
Used with chemicals, biological, and non-biological substances for their composition, structure, characterization, and properties; also used for the chemical composition or content of organs, tissue, tumors, body fluids, organisms, and plants. Excludes chemical analysis and determination of substances for which "analysis" is used; excludes synthesis for which "chemical synthesis" is used; excludes isolation and purification of substances for which "isolation & purification" is used.
(A11, A15, B, C, D, E1-4, E6, E7, F3, G1, G2, I2, I3, J, M, N2-4) CL, class
Used for taxonomic or other systematic or hierarchical classification systems.
(C, F3) CO, compl
Used with diseases to indicate conditions that co-exist or follow, i.e., co-existing diseases, complications, or sequelae.
(C1-12, C14, C15, C17, C19-23) CN, congen
Used with disease headings to indicate those conditions existing at, and usually before, birth. It excludes morphologic abnormalities and birth injuries, for which "abnormalities" and "injuries" are used.
(D, E1, E3, E4, E6, E7) CT, contra
Used with drugs, chemicals, and biological and physical agents in any disease or physical state that might render their use improper, undesirable, or inadvisable. Used also with contraindicated diagnostic, therapeutic, prophylactic, anesthetic, surgical or other procedures.
(A2-10, A12-17, B1, B3, B5-7) CY, cytol
Used for normal cellular morphology of unicellular and multicellular organisms.
(D8, D12) DF, defic
Used with endogenous and exogenous substances which are absent or in diminished amount relative to the normal requirement of an organism or a biologic system.
(C, F3) DI, diag
Used with diseases for all aspects of diagnosis, including examination, differential diagnosis and prognosis; excludes mass screening for which "prevention & control" is used. Excludes radiographic diagnosis for which "radiography" is used; excludes scintigraphic diagnosis for which "radionuclide imaging" is used; excludes ultrasonic diagnosis for which "ultrasonography" is used.
(D) DU, diag use
Used with chemical compounds, drugs, and physical agents when these substances are used for studies of clinical function of an organ, or for the diagnosis of human or animal diseases.
(C, F3) DH, diet ther
Used with disease headings for dietary and nutritional management of the disease. The concept does not include vitamin or mineral supplements, for which "drug therapy" may be used.
(A2-17, B1, B3-7, D8, D12, G4-11, G14) DE, drug eff
Used with organs, regions, tissues, or organisms and physiological and psychological processes for the effects of drugs and chemicals.
(C, F3) DT, drug ther
Used with disease headings for the treatment of disease by the administration of drugs, chemicals, and antibiotics. For diet therapy and radiotherapy, use specific subheadings. Excludes immunotherapy for which "therapy" is used.
(C, D, E, F3, G1, G2, I2, I3, J, N2-4) EC, econ
Used for the economic aspects of any subject, as well as for all aspects of financial management. It includes the raising or providing of funds.
(E4, G1, G2) ED, educ
Used for education, training programs, and courses in various fields and disciplines, and for training groups of persons.
(A1-5, A7-10, A13, A14, A17, B2, B6, C) EM, embryol
Used with organs, regions, and animal headings for embryologic and fetal development. It is used also with diseases for embryologic factors contributing to postnatal disorders.
(A2-17, B1, B3-7, C, F3) EN, enzymol
Used with organisms, except vertebrates, and with organs and tissues. It is also used with diseases for enzymes during the course of the disease, but excludes diagnostic enzyme tests, for which "diagnosis" is used.
(C, F3, Z) EP, epidemiol
Used with human and veterinary diseases for the distribution of disease, factors which cause disease, and the attributes of disease in defined populations; includes incidence, frequency, prevalence, endemic and epidemic outbreaks; also surveys and estimates of morbidity in geographic areas and in specified populations. Used also with geographical headings for the location of epidemiologic aspects of a disease. Excludes mortality for which "mortality" is used.
(E1-4, E6, E7, F3, G1, G2, G4-11, I2, I3, J1, N2-4) ES, eth
Used with techniques and activities for discussion and analysis with respect to human and social values.
(C1-21, C23, F3, Z) EH, ethnol
Used with diseases and selected terms for ethnic, cultural, anthropological, or racial aspects, and with geographic headings to indicate the place of origin of a group of people.
(C, F3) ET, etiol
Used with diseases for causative agents including microorganisms and includes environmental and social factors and personal habits as contributing factors. It includes pathogenesis.
(B, C, D6, D8, D11-13, D17, D24, F3, G4-11, G14) GE, genet
Used for mechanisms of heredity and the genetics of organisms, for the genetic basis of normal and pathologic states, and for the genetic aspects of endogenous chemicals. It includes biochemical and molecular influence on genetic material.
growth & development
(A1-5, A7-10, A13, A14, A17, B) GD, growth
Used with microorganisms, plants, and the postnatal period of animals for growth and development. It includes also the postnatal growth or development of organs or anatomical parts.
(C, D, E, F3, F4, G1, G2, I, J, M, N2-4) HI, hist
Used for the historical aspects of any subject. It includes brief historical notes but excludes case histories.
(A2-17, B, C, D1-24, D27, F3, G4-10, G14) IM, immunol
Used for immunologic studies of tissues, organs, microorganisms, fungi, viruses, and animals. It includes immunologic aspects of diseases but not immunologic procedures used for diagnostic, preventive, or therapeutic purposes, for which "diagnosis", "prevention & control", or "therapy" are used. The concept is also used for chemicals as antigens or haptens.
(A1-5, A7-10, A13, A14, A17, B2) IN, inj
Used with anatomic headings, animals, and sports for wounds and injuries. Excludes cell damage, for which "pathology" is used.
(A1-5, A7, A9, A10, A13, A14, A17) IR, innerv
Used with organs, regions, or tissues for their nerve supply.
(E1-5, G1, G2) IS, instrum
Used with diagnostic or therapeutic procedures, analytic techniques, and specialties or disciplines, for the development or modification of apparatus, instruments, or equipment.
isolation & purification
(B3-5, B7, D) IP, isol
Used with bacteria, viruses, fungi, protozoa, and helminths for the obtaining of pure strains or for the demonstration of the presence of or identification of organisms by DNA analyses, immunologic, or other methods, including culture techniques. It is used also with biological substances and chemicals for the isolation and purification of the constituents.
legislation & jurisprudence
(E4, G1, G2, I2, I3, M, N2-4) LJ, legis
Used for laws, statutes, ordinances, or government regulations, as well as for legal controversy and court decisions.
(G1, G2) MA, man
Used with disciplines and programs for the demand, supply, distribution, recruitment, and use of personnel.
(A2-17, B, C, D, F3) ME, metab
Used with organs, cells and subcellular fractions, organisms, and diseases for biochemical changes and metabolism. It is used also with drugs and chemicals for catabolic changes (breakdown of complex molecules into simpler ones). For anabolic processes (conversion of small molecules into large), BIOSYNTHESIS is used. For enzymology, pharmacokinetics, and secretion use the specific subheadings.
(E1-5, G1, G2) MT, methods
Used with techniques, procedures, and programs for methods.
(A, B1, B2, B6, C, E7, F3, J2) MI, microbiol
Used with organs, animals, and higher plants and with diseases for microbiologic studies. For parasites, "parasitology" is used; for viruses, "virology" is used.
(C, E1, E3, E4, F3) MO, mortal
Used with human and veterinary diseases for mortality statistics. For deaths resulting from various procedures statistically but for a death resulting in a specific case, use FATAL OUTCOME, not /mortality.
(C, E1, E3, E4, F3) NU, nurs
Used with diseases for nursing care and techniques in their management. It includes the nursing role in diagnostic, therapeutic, and preventive procedures.
organization & administration
(G1, G2, I2, N2, N4) OG, organ
Used for administrative structure and management.
(A, B1, B2, B6, C, E7, F3, J2) PS, parasitol
Used with animals, higher plants, organs, and diseases for parasitic factors. In diseases, it is not used if the parasitic involvement is implicit in the diagnosis.
(B1, B3-5, B7) PY, pathogen
Used with microorganisms, viruses, and parasites for studies of their ability to cause disease in man, animals, or plants.
(A1-11, A13-17, C, F3) PA, pathol
Used for organ, tissue, or cell structure in disease states.
(D1-23, D25-27) PK, pharmacokin
Used for the mechanism, dynamics and kinetics of exogenous chemical and drug absorption, biotransformation, distribution, release, transport, uptake and elimination as a function of dosage, extent and rate of metabolic processes.
(D) PD, pharmacol
Used with drugs and exogenously administered chemical substances for their effects on living tissues and organisms. It includes acceleration and inhibition of physiological and biochemical processes and other pharmacologic mechanisms of action.
(A, B, D6, D8, D11-13, D17, D24, G4-11, G14) PH, physiol
Used with organs, tissues, and cells of unicellular and multicellular organisms for normal function. It is used also with biochemical substances, endogenously produced, for their physiologic role.
(A1-5, A7-10, A13, A14, A17, C, F3) PP, physiopathol
Used with organs and diseases for disordered function in disease states.
(B6, D, J2) PO, pois
Used with drugs, chemicals, and industrial materials for human or animal poisoning, acute or chronic, whether the poisoning is accidental, occupational, suicidal, by medication error, or by environmental exposure.
prevention & control
(C, F3) PC, prev
Used with disease headings for increasing human or animal resistance against disease (e.g., immunization), for control of transmission agents, for prevention and control of environmental hazards, or for prevention and control of social factors leading to disease. It includes preventive measures in individual cases.
(C, E1-4, E6, F3, I3, M) PX, psychol
Used with non-psychiatric diseases, techniques, and named groups for psychologic, psychiatric, psychosomatic, psychosocial, behavioral, and emotional aspects, and with psychiatric disease for psychologic aspects; used also with animal terms for animal behavior and psychology.
(A, B1, B3-7, D, G4-11, G14, J2) RE, rad eff
Used for effects of ionizing and nonionizing radiation upon living organisms, organs and tissues, and their constituents, and upon physiologic processes. It includes the effect of irradiation on drugs and chemicals.
(A, C, F3) RA, radiogr
Used with organs, regions, and diseases for x-ray examinations. It does not include radionuclide imaging for which "radionuclide imaging" is used.
(A, C, F3) RI, radionuclide
Used for radionuclide imaging of any anatomical structure, or for the diagnosis of disease.
(C) RT, radiother
Used with disease headings for the therapeutic use of ionizing and nonionizing radiation. It includes the use of radioisotope therapy.
(C1-21, C23, E4, F3) RH, rehabil
Used with diseases and surgical procedures for restoration of function of the individual.
(C4) SC, second
Used with neoplasms to indicate the secondary location to which the neoplastic process has metastasized.
(A2-16, C4, D6, D8, D11-13) SE, secret
Used for the discharge across the cell membrane, into the intracellular space or ducts, of endogenous substances resulting from the activity of intact cells of glands, tissues, or organs.
(D1-23, D25-27, E, F4, G1, G2, I2, J, N2-4) ST, stand
Used with facilities, personnel, and program headings for the development, testing, and application of standards of adequacy or acceptable performance and with chemicals and drugs for standards of identification, quality, and potency. It includes health or safety standards in industries and occupations.
statistics & numerical data
(E, F4, G1, G2, I2, I3, J1, M, N2-4) SN, statist
Used with non-disease headings for the expression of numerical values which describe particular sets or groups of data. It excludes manpower distribution for which "manpower" is used and excludes supply or demand for which "supply & distribution" is used.
supply & distribution
(D1-23, D25-27, E7, J2) SD, supply
Used for the quantitative availability and distribution of material, equipment, health services, personnel, and facilities. It excludes food supply and water supply in industries and occupations.
(A1-5, A7-10, A13, A14, A17, B2, C, F3) SU, surg
Used for operative procedures on organs, regions, or tissues in the treatment of diseases, including tissue section by lasers. It excludes transplantation, for which "transplantation" is used.
(D) TU, ther use
Used with drugs, biological preparations, and physical agents for their use in the prophylaxis and treatment of disease. It includes veterinary use.
(C, F3) TH, ther
Used with diseases for therapeutic interventions except drug therapy, diet therapy, radiotherapy, and surgery, for which specific subheadings exist. The concept is also used for articles and books dealing with multiple therapies.
(B6, D, J2) TO, tox
Used with drugs and chemicals for experimental human and animal studies of their ill effects. It includes studies to determine the margin of safety or the reactions accompanying administration at various dose levels. It is used also for experimental studies of exposure to environmental agents.
(C1-3, C22) TM, transm
Used with diseases for studies of the modes of transmission.
(A2, A3, A5-11, A13-17) TR, transpl
Used with organs, tissues, or cells for transplantation from one site to another within the same subject, or from one subject to another of the same species or different species.
(E1-4, E6, E7, G1, G2, I2, I3, N2-4) TD, trends
Used for the manner in which a subject changes, qualitatively or quantitatively, with time, whether past, present, or future. It excludes discussions of the course of disease in particular patients.
(A, C, F3) US, ultrasonogr
Used with organs and regions for ultrasonic imaging and with diseases for ultrasonic diagnosis. Does not include ultrasonic therapy.
(A2-11, A13-17, B1, B3-7, C4, D8, D12) UL, ultrastruct
Used with tissues and cells (including neoplasms) and microorganisms for microanatomic structures, generally below the size visible by light microscopy.
(B2, C, D1-24, D27, F3) UR, urine
Used for the presence or analysis of substances in the urine, and also for the examination of, or changes in, the urine in disease.
(E1-4, E6, E7, N2, N4) UT, util
Used with equipment, facilities, programs, services, and health personnel for discussions, usually with data, of how much they are used. It includes discussions of overuse and underuse.
(C1-21, C23, E1, E3, E4, E6, E7) VE, vet
Used for naturally occurring diseases in animals, or for diagnostic, preventive, or therapeutic procedures used in veterinary medicine.
(A, B1-3, B5-7, C, E7, F3, J2) VI, virol
Used with organs, animals, and higher plants and with diseases for virologic studies. For bacteria, rickettsia, and fungi, "microbiology" is used; for parasites, "parasitology" is used.
U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894
National Institutes of Health, Department of Health & Human Services
Copyright, Privacy, Accessibility
Last updated: 18 October 2002