Medical Terms in Lay Language (2024)

Please use these descriptions in place of medical jargon in consent documents, recruitment materials and other study documents. Note: These terms are not the only acceptable plain language alternatives for these vocabulary words.

This glossary of terms is derived from a list copyrighted by the University of Kentucky, Office of Research Integrity (1990).

For clinical research-specific definitions, see also the Clinical Research Glossary developed by the Multi-Regional Clinical Trials (MRCT) Center of Brigham and Women’s Hospital and Harvardand the Clinical Data Interchange Standards Consortium (CDISC).

Alternative Lay Language for Medical Terms for use in Informed Consent Documents



ABDOMEN/ABDOMINAL body cavity below diaphragm that contains stomach, intestines, liver and other organs
ABSORB take up fluids, take in
ACIDOSIS condition when blood contains more acid than normal
ACUITY clearness, keenness, esp. of vision and airways
ACUTE new, recent, sudden, urgent
ADENOPATHY swollen lymph nodes (glands)
ADJUVANT helpful, assisting, aiding, supportive
ADJUVANT TREATMENT added treatment (usually to a standard treatment)
ANTIBIOTIC drug that kills bacteria and other germs
ANTIMICROBIAL drug that kills bacteria and other germs
ANTIRETROVIRAL drug that works against the growth of certain viruses
ADVERSE EFFECT side effect, bad reaction, unwanted response
ALLERGIC REACTION rash, hives, swelling, trouble breathing
ANAPHYLAXIS serious, potentially life-threatening allergic reaction
ANEMIA decreased red blood cells; low red cell blood count
ANESTHETIC a drug or agent used to decrease the feeling of pain, or eliminate the feeling of pain by putting you to sleep
ANGINA pain resulting from not enough blood flowing to the heart
ANGINA PECTORIS pain resulting from not enough blood flowing to the heart
ANOREXIA disorder in which person will not eat; lack of appetite
ANTECUBITAL related to the inner side of the forearm
ANTIBODY protein made in the body in response to foreign substance
ANTICONVULSANT drug used to prevent seizures
ANTILIPEMIC a drug that lowers fat levels in the blood
ANTITUSSIVE a drug used to relieve coughing
ARRHYTHMIA abnormal heartbeat; any change from the normal heartbeat
ASPIRATION fluid entering the lungs, such as after vomiting
ASSAY lab test
ASSESS to learn about, measure, evaluate, look at
ASTHMA lung disease associated with tightening of air passages, making breathing difficult
ASYMPTOMATIC without symptoms
AXILLA armpit


BENIGN not malignant, without serious consequences
BID twice a day
BINDING/BOUND carried by, to make stick together, transported
BIOAVAILABILITY the extent to which a drug or other substance becomes available to the body
BLOOD PROFILE series of blood tests
BOLUS a large amount given all at once
BONE MASS the amount of calcium and other minerals in a given amount of bone
BRADYARRHYTHMIAS slow, irregular heartbeats
BRADYCARDIA slow heartbeat
BRONCHOSPASM breathing distress caused by narrowing of the airways


CARCINOGENIC cancer-causing
CARCINOMA type of cancer
CARDIAC related to the heart
CARDIOVERSION return to normal heartbeat by electric shock
CATHETER a tube for withdrawing or giving fluids
CATHETER a tube placed near the spinal cord and used for anesthesia (indwelling epidural) during surgery
CENTRAL NERVOUS SYSTEM (CNS) brain and spinal cord
CEREBRAL TRAUMA damage to the brain
CESSATION stopping
CHD coronary heart disease
CHEMOTHERAPY treatment of disease, usually cancer, by chemical agents
CHRONIC continuing for a long time, ongoing
CLINICAL pertaining to medical care
CLINICAL TRIAL an experiment involving human subjects
COMA unconscious state
COMPLETE RESPONSE total disappearance of disease
CONGENITAL present before birth
CONJUNCTIVITIS redness and irritation of the thin membrane that covers the eye
CONSOLIDATION PHASE treatment phase intended to make a remission permanent (follows induction phase)
CONTROLLED TRIAL research study in which the experimental treatment or procedure is compared to a standard (control) treatment or procedure
COOPERATIVE GROUP association of multiple institutions to perform clinical trials
CORONARY related to the blood vessels that supply the heart, or to the heart itself
CT SCAN (CAT) computerized series of x-rays (computerized tomography)
CULTURE test for infection, or for organisms that could cause infection
CUMULATIVE added together from the beginning
CUTANEOUS relating to the skin
CVA stroke (cerebrovascular accident)


DERMATOLOGIC pertaining to the skin
DIASTOLIC lower number in a blood pressure reading
DISTAL toward the end, away from the center of the body
DIURETIC "water pill" or drug that causes increase in urination
DOPPLER device using sound waves to diagnose or test
DOUBLE BLIND study in which neither investigators nor subjects know what drug or treatment the subject is receiving
DYSFUNCTION state of improper function
DYSPLASIA abnormal cells


ECHOCARDIOGRAM sound wave test of the heart
EDEMA excess fluid collecting in tissue
EEG electric brain wave tracing (electroencephalogram)
EFFICACY effectiveness
ELECTROCARDIOGRAM electrical tracing of the heartbeat (ECG or EKG)
ELECTROLYTE IMBALANCE an imbalance of minerals in the blood
EMESIS vomiting
EMPIRIC based on experience
ENDOSCOPIC EXAMINATION viewing an internal part of the body with a lighted tube
ENTERAL by way of the intestines
EPIDURAL outside the spinal cord
ERADICATE get rid of (such as disease) Page 2 of 7
EVALUATED, ASSESSED examined for a medical condition
EXPEDITED REVIEW rapid review of a protocol by the IRB Chair without full committee approval, permitted with certain low-risk research studies
EXTERNAL outside the body
EXTRAVASATE to leak outside of a planned area, such as out of a blood vessel


FDA U.S. Food and Drug Administration, the branch of federal government that approves new drugs
FIBROUS having many fibers, such as scar tissue
FIBRILLATION irregular beat of the heart or other muscle


GENERAL ANESTHESIA pain prevention by giving drugs to cause loss of consciousness, as during surgery
GESTATIONAL pertaining to pregnancy


HEMATOCRIT amount of red blood cells in the blood
HEMATOMA a bruise, a black and blue mark
HEMOLYSIS breakdown in red blood cells
HEPARIN LOCK needle placed in the arm with blood thinner to keep the blood from clotting
HEPATOMA cancer or tumor of the liver
HERITABLE DISEASE can be transmitted to one’s offspring, resulting in damage to future children
HISTOPATHOLOGIC pertaining to the disease status of body tissues or cells
HOLTER MONITOR a portable machine for recording heart beats
HYPERCALCEMIA high blood calcium level
HYPERKALEMIA high blood potassium level
HYPERNATREMIA high blood sodium level
HYPERTENSION high blood pressure
HYPOCALCEMIA low blood calcium level
HYPOKALEMIA low blood potassium level
HYPONATREMIA low blood sodium level
HYPOTENSION low blood pressure
HYPOXEMIA a decrease of oxygen in the blood
HYPOXIA a decrease of oxygen reaching body tissues
HYSTERECTOMY surgical removal of the uterus, ovaries (female sex glands), or both uterus and ovaries


IATROGENIC caused by a physician or by treatment
IDE investigational device exemption, the license to test an unapproved new medical device
IDIOPATHIC of unknown cause
IMMUNITY defense against, protection from
IMMUNOGLOBIN a protein that makes antibodies
IMMUNOSUPPRESSIVE drug which works against the body's immune (protective) response, often used in transplantation and diseases caused by immune system malfunction
IMMUNOTHERAPY giving of drugs to help the body's immune (protective) system; usually used to destroy cancer cells
IMPAIRED FUNCTION abnormal function
IMPLANTED placed in the body
IND investigational new drug, the license to test an unapproved new drug
INDUCTION PHASE beginning phase or stage of a treatment
INDURATION hardening
INDWELLING remaining in a given location, such as a catheter
INFARCT death of tissue due to lack of blood supply
INFECTIOUS DISEASE transmitted from one person to the next
INFLAMMATION swelling that is generally painful, red, and warm
INFUSION slow injection of a substance into the body, usually into the blood by means of a catheter
INGESTION eating; taking by mouth
INTERFERON drug which acts against viruses; antiviral agent
INTERMITTENT occurring (regularly or irregularly) between two time points; repeatedly stopping, then starting again
INTERNAL within the body
INTERIOR inside of the body
INTRAMUSCULAR into the muscle; within the muscle
INTRAPERITONEAL into the abdominal cavity
INTRATHECAL into the spinal fluid
INTRAVENOUS (IV) through the vein
INTRAVESICAL in the bladder
INTUBATE the placement of a tube into the airway
INVASIVE PROCEDURE puncturing, opening, or cutting the skin
INVESTIGATIONAL NEW DRUG (IND) a new drug that has not been approved by the FDA
INVESTIGATIONAL METHOD a treatment method which has not been proven to be beneficial or has not been accepted as standard care
ISCHEMIA decreased oxygen in a tissue (usually because of decreased blood flow)


LAPAROTOMY surgical procedure in which an incision is made in the abdominal wall to enable adoctor to look at the organs inside
LESION wound or injury; a diseased patch of skin
LETHARGY sleepiness, tiredness
LEUKOPENIA low white blood cell count
LIPID CONTENT fat content in the blood
LIPID PROFILE (PANEL) fat and cholesterol levels in the blood
LOCAL ANESTHESIA creation of insensitivity to pain in a small, local area of the body, usually by injection of numbing drugs
LOCALIZED restricted to one area, limited to one area
LUMEN the cavity of an organ or tube (e.g., blood vessel)
LYMPHANGIOGRAPHY an x-ray of the lymph nodes or tissues after injecting dye into lymph vessels (e.g., in feet)
LYMPHOCYTE a type of white blood cell important in immunity (protection) against infection
LYMPHOMA a cancer of the lymph nodes (or tissues)


MALAISE a vague feeling of bodily discomfort, feeling badly
MALFUNCTION condition in which something is not functioning properly
MALIGNANCY cancer or other progressively enlarging and spreading tumor, usually fatal if notsuccessfully treated
MEDULLABLASTOMA a type of brain tumor
MEGALOBLASTOSIS change in red blood cells
METABOLIZE process of breaking down substances in the cells to obtain energy
METASTASIS spread of cancer cells from one part of the body to another
METRONIDAZOLE drug used to treat infections caused by parasites (invading organisms that take up living in the body) or other causes of anaerobic infection (not requiring oxygen to survive)
MI myocardial infarction, heart attack
MINIMAL slight
MINIMIZE reduce as much as possible Page 4 of 7
MONITOR check on; keep track of; watch carefully
MOBILITY ease of movement
MORBIDITY undesired result or complication
MOTILITY the ability to move
MRI magnetic resonance imaging, diagnostic pictures of the inside of the body, created using magnetic rather than x-ray energy
MUCOSA, MUCOUS MEMBRANE moist lining of digestive, respiratory, reproductive, and urinary tracts
MYALGIA muscle aches
MYOCARDIAL pertaining to the heart muscle


NASOGASTRIC TUBE placed in the nose, reaching to the stomach
NCI the National Cancer Institute
NECROSIS death of tissue
NEOPLASIA/NEOPLASM tumor, may be benign or malignant
NEUROBLASTOMA a cancer of nerve tissue
NEUROLOGICAL pertaining to the nervous system
NEUTROPENIA decrease in the main part of the white blood cells
NIH the National Institutes of Health
NONINVASIVE not breaking, cutting, or entering the skin
NOSOCOMIAL acquired in the hospital


OCCLUSION closing; blockage; obstruction
ONCOLOGY the study of tumors or cancer
OPHTHALMIC pertaining to the eye
OPTIMAL best, most favorable or desirable
ORTHOPEDIC pertaining to the bones
OSTEOPETROSIS rare bone disorder characterized by dense bone
OSTEOPOROSIS softening of the bones
OVARIES female sex glands


PARENTERAL given by injection
PATENCY condition of being open
PATHOGENESIS development of a disease or unhealthy condition
PERCUTANEOUS through the skin
PERIPHERAL not central
PER OS (PO) by mouth
PHARMAco*kINETICS the study of the way the body absorbs, distributes, and gets rid of a drug
PHASE I first phase of study of a new drug in humans to determine action, safety, and proper dosing
PHASE II second phase of study of a new drug in humans, intended to gather information about safety and effectiveness of the drug for certain uses
PHASE III large-scale studies to confirm and expand information on safety and effectiveness of new drug for certain uses, and to study common side effects
PHASE IV studies done after the drug is approved by the FDA, especially to compare it to standard care or to try it for new uses
PHLEBITIS irritation or inflammation of the vein
PLACEBO an inactive substance; a pill/liquid that contains no medicine
PLACEBO EFFECT improvement seen with giving subjects a placebo, though it contains no active drug/treatment
PLATELETS small particles in the blood that help with clotting
POTENTIAL possible
POTENTIATE increase or multiply the effect of a drug or toxin (poison) by giving another drug or toxin at the same time (sometimes an unintentional result)
POTENTIATOR an agent that helps another agent work better
PRENATAL before birth
PROPHYLAXIS a drug given to prevent disease or infection
PER OS (PO) by mouth
PRN as needed
PROGNOSIS outlook, probable outcomes
PRONE lying on the stomach
PROSPECTIVE STUDY following patients forward in time
PROSTHESIS artificial part, most often limbs, such as arms or legs
PROTOCOL plan of study
PROXIMAL closer to the center of the body, away from the end
PULMONARY pertaining to the lungs


QD every day; daily
QID four times a day


RADIATION THERAPY x-ray or cobalt treatment
RANDOM by chance (like the flip of a coin)
RANDOMIZATION chance selection
RBC red blood cell
RECOMBINANT formation of new combinations of genes
RECONSTITUTION putting back together the original parts or elements
RECUR happen again
REFRACTORY not responding to treatment
REGENERATION re-growth of a structure or of lost tissue
REGIMEN pattern of giving treatment
RELAPSE the return of a disease
REMISSION disappearance of evidence of cancer or other disease
RENAL pertaining to the kidneys
REPLICABLE possible to duplicate
RESECT remove or cut out surgically
RETROSPECTIVE STUDY looking back over past experience


SARCOMA a type of cancer
SEDATIVE a drug to calm or make less anxious
SEMINOMA a type of testicular cancer (found in the male sex glands)
SEQUENTIALLY in a row, in order
SOMNOLENCE sleepiness
SPIROMETER an instrument to measure the amount of air taken into and exhaled from the lungs
STAGING an evaluation of the extent of the disease
STANDARD OF CARE a treatment plan that the majority of the medical community would accept as appropriate
STENOSIS narrowing of a duct, tube, or one of the blood vessels in the heart
STOMATITIS mouth sores, inflammation of the mouth
STRATIFY arrange in groups for analysis of results (e.g., stratify by age, sex, etc.)
STUPOR stunned state in which it is difficult to get a response or the attention of the subject
SUBCLAVIAN under the collarbone
SUBCUTANEOUS under the skin
SUPINE lying on the back
SUPPORTIVE CARE general medical care aimed at symptoms, not intended to improve or cure underlying disease
SYMPTOMATIC having symptoms
SYNDROME a condition characterized by a set of symptoms
SYSTOLIC top number in blood pressure; pressure during active contraction of the heart


TERATOGENIC capable of causing malformations in a fetus (developing baby still inside the mother’s body)
TESTES/testicl*S male sex glands
THROMBUS blood clot
TID three times a day
TITRATION a method for deciding on the strength of a drug or solution; gradually increasing the dose
T-LYMPHOCYTES type of white blood cells
TOPICAL on the surface
TOPICAL ANESTHETIC applied to a certain area of the skin and reducing pain only in the area to which applied
TOXICITY side effects or undesirable effects of a drug or treatment
TRANSDERMAL through the skin
TRANSIENTLY temporarily
TRAUMA injury; wound
TREADMILL walking machine used to test heart function


UPTAKE absorbing and taking in of a substance by living tissue


VALVULOPLASTY plastic repair of a valve, especially a heart valve
VARICES enlarged veins
VASOSPASM narrowing of the blood vessels
VECTOR a carrier that can transmit disease-causing microorganisms (germs and viruses)
VENIPUNCTURE needle stick, blood draw, entering the skin with a needle


WBC white blood cell

Medical Terms in Lay Language (2024)
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