| Word | Definition |
| I | iodine |
| -ia | condition, state, disease |
| -iasis | condition, state |
| iatr/o | treatment, medicine |
| IBD | inflammatory bowel disease |
| IBS | irritable bowel syndrome |
| ibuprofen | A nonsteroidal anti-inflammatory agent with analgesic properties used in the therapy of rheumatism and arthritis. |
| IBW | ideal body weight |
| IC | inspiratory capacity |
| -ic | pertaining to |
| ICD | implantable cardiac defibrillator |
| ICF | intermediate care facility |
| ichthyosis | A family of skin disorders characterized by dry, thickened skin. |
| -ician | specialist, practitioner |
| ICP | intracranial pressure |
| ICS | intercostal space |
| ICSH | interstitial cell-stimulating hormone |
| icter/o | jaundice |
| ictus | An attack, blow, stroke, or seizure. |
| ICU | intensive care unit |
| id | The part of the personality structure which harbors the unconscious instinctive desires and strivings of the individual. |
| ide/o | idea |
| idi/o | distinct |
| IDM | infants of diabetic mothers |
| IED | improvised explosive device |
| IF | interferon |
| Ig | immunoglobulin |
| IGT | impaired glucose tolerance |
| ile/o | ileum (final section of small intestine) |
| ileal | Of or pertaining to the ileum. |
| ileectomy | Surgical removal of the ileum. |
| ileitis | Inflammation of any segment of the ileum. |
| ileostomy | A surgical construction of an opening into the ileum on the abdominal wall. |
| ileum | The distal and narrowest portion of the small intestine, between the jejunum and the ileocecal valve of the large intestine. |
| Ileus | Impairment of the normal flow of the intestinal contents within the bowel. |
| ili/o | ilium (uppermost and largest bone of the pelvis) |
| iliac artery | Either of two large arteries originating from the abdominal aorta; they supply blood to the pelvis, abdominal wall and legs. |
| ilium | The largest of three bones that make up each half of the pelvic girdle. |
| illusion | An error in perception. |
| IM | intramuscular |
| immobilization | The restriction of the movement of whole or part of the body. |
| immun/o | immune, safe |
| immunity | Protection from diseases, particularly infectious diseases. |
| immunization | A process for building or augmenting resistance to an infectious disease. |
| immunoglobulins | An infection-fighting protein in the blood or secretory fluids that helps destroy bacteria, viruses and toxins. |
| immunosuppressant | Deliberate prevention or diminution of the host's immune response. |
| immunotherapy | Manipulation of the host's immune system in treatment of disease. |
| imperforate | Not open. |
| impetigo | A contagious skin condition common in children, caused by streptococcus, staphylococcus. |
| impingement syndrome | The result of chronic and repetitive compression of the rotator-cuff tendons in the shoulder. |
| implant | To embed. |
| impotence | The inability to sustain a penile erection to allow normal vaginal intercourse. |
| impulsive behavior | An act performed without delay, reflection, voluntary direction or obvious control in response to a stimulus. |
| IMV | intermittent mandatory ventilation |
| in vitro | In a glass. In an artificial environment outside a living organism |
| in- | in, not or fiber |
| incidence | The number of new cases of a given disease during a specified period in a population. |
| incineration | High temperature destruction of waste by burning with reduction to ashes. |
| incision | A cut made by a medical professional. |
| incisor | Any of the four maxillary and four mandibular teeth, having a sharp incisal edge. |
| incontinence | The inability to control the flow of urine from the bladder. |
| incubation | Maintaining optimal environmental conditions for the growth of microbial or tissue cultures. Also, the time period between exposure to an infectious agent and the appearance of symptoms. |
| IND | investigational new drug |
| indication | The basis, evidence or rationale for using a particular treatment or diagnostic test. |
| induction | Causing to occur. |
| inf. | inferior |
| infant | A child between 1 and 23 months of age. |
| infarction | Tissue death due to lack of oxygen |
| infection | The invasion of the body by disease causing agents and the body's reaction. |
| infectious myringitis | An infection causing painful blisters on the eardrum. More often seen in children than adults. Causal agent is Mycoplasma. |
| inferior | below |
| infertility | Inability to conceive and produce viable offspring. |
| inflammation | The response of body tissues to injury, irritation or infection. Usually manifested by the signs of pain, heat, redness and swelling. |
| influenza | Acute, contagious viral infection of the respiratory system. |
| infra- | below, down, under |
| infusion pumps | A device that delivers intravenous fluids at low doses and at a controllable rate. |
| inguin/o | groin |
| inguinal canal | A tunnel in the abdominal wall through which a testis descends into the scrotum. |
| inhalation | Breathing in. |
| inj. | injection |
| injections | Introduction of substances into the body using a needle and syringe. |
| insecticides | Agents used to control insects. |
| insemination | The deposit of seminal fluid within the vagina. |
| insomnia | Inability to sleep. |
| insulin | A hormone produced in the pancreas. Regulates glucose levels. |
| insulinoma | A neoplasm of the pancreas that is one of the chief causes of hypoglycemia. |
| integumentary system | The outer covering of the body composed of the skin and the skin appendages, which are the hair, the nails; and the sebaceous glands and the sweat glands and their ducts. |
| inter- | between |
| intercellular | Between the cells. |
| interferon | A class of small protein and glycoprotein cytokines produced by T cells, fibroblasts, and other cells in response to viral infection and other biologic and synthetic stimuli. |
| interferons | Proteins that are produced by the body's cells as a defensive response to pathogens. |
| intermittency | A urinary tract disorder in which urine flow is not continuous but stops and starts. |
| intermittent claudication | Muscle pain caused by too little blood flow, usually during exercise. |
| internal medicine | A medical specialty concerned with the diagnosis and treatment of internal organ diseases. |
| interneurons | Groups or combinations of neurons between sensory and motor neurons that govern coordinated activity. |
| interphase | The interval between cell divisions during which the chromosomes are not individually distinguishable. |
| interstitial | Small space(s) between biological structures. |
| interstitial cystitis | Painful bladder syndrome. |
| intertrigo | A superficial dermatitis occurring in areas where skin surfaces come into contact with, and chafe, each other. The condition is caused by moisture and friction. |
| intestines | The section of the alimentary canal from the stomach to the anal canal. |
| intolerance | A patient's inability to tolerate a drug. |
| intra- | within |
| intracellular | Inside a cell. |
| intracranial | Within the skull. |
| intracranial embolism | Blocking of a blood vessel in the skull by an embolus which can be a thrombus or other undissolved material in the blood stream. |
| intracranial hematoma | Blood accumulation within the brain or between the brain and the skull, |
| intraductal papilloma | Benign tumors that grow within the breast ducts |
| intrathecal | Within a sheath. |
| intrauterine | Within the uterine cavity. |
| intravenous | Within a vein. |
| intrinsic muscle | A muscle whose origin and insertion are both in the same part or organ. |
| intro- | within |
| introversion | A state in which attention is largely directed inward upon one's self, with diminished interest in the outside world. |
| intubation | The insertion of a tube, as into the larynx. |
| intuition | Knowing without conscious use of reasoning. |
| intussusception | The movement of a bowel segment into an adjacent segment in the manner of a telescope. The condition is commonest in children. |
| inulin | A starch found in the tubers and roots of many plants. It is used as a diagnostic aid in tests of kidney function |
| invasion | The entry and proliferation of a pathogen or tumor. |
| invertebrates | Animals lacking a spinal column. |
| involucrum | An enveloping sheath. |
| iod/o | iodine |
| iodine | A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53. In a solution, it is anti-infective and is used topically. |
| ion | An atom that has a positive or negative electric charge due to a gain or loss of one or more electrons. |
| ion/o | ion |
| iontophoresis | Therapeutic introduction of ions of soluble salts into tissues by means of electric current. |
| -ior | pertaining to |
| ipecac | An emetic. |
| IPPB | intermittent positive pressure breathing |
| ipsi- | same |
| IQ | intelligence quotient |
| IRB | institutional review board |
| irid/o | iris |
| iridectomy | Surgical removal of part of the iris. |
| iridescence | Shining or glittering with the colors of the rainbow |
| iridoplegia | Paralysis of the sphincter muscle of the iris or the dilator muscle |
| iris | The circular pigmented membrane behind the cornea of the eye that gives the eye its color. The iris surrounds a central opening called the pupil. |
| iritis | Inflammation of the iris. |
| irradiation | Exposure to ionizing radiation. |
| irrigation | The washing out of a wound using a continuous flow of water or solution. |
| IRV | inspiratory reserve volume |
| is/o | equal |
| isch/o | suppress |
| ischemia | A hypoperfusion of blood through an organ or tissue caused by a obstruction of blood vessels. |
| ischemic heart disease | Recurring chest pain or discomfort when a part of the heart does not receive enough blood. Often triggered by exertion or excitement. |
| ischemic stroke | The main type of stroke. Occur when a blood vessel that supplies blood to the brain is blocked by a blood clot. |
| ischium | The inferior, dorsal portion of the hip bone. |
| islet | A small island. |
| -ism | condition, process |
| -ismus | spasm, contraction |
| isoantigens | An antigenic substance that occurs only in some individuals of a species, such as the blood group antigens of humans. |
| isolation | The separation of a person with an infectious disease from other people. |
| isomorphism | The condition of two or more objects being similar in shape or structure. |
| isotonic contraction | Muscle contraction with negligible change in the force of contraction but shortening of the distance between the origin and insertion. |
| isotonic solutions | Solutions having the same osmotic pressure. |
| isotopes | Atoms of an element species differing in mass number but having the same atomic number. |
| -ist | person who specializes |
| isthmus | A narrow part of an organ or body part. |
| -ite | resembling, the nature of |
| -ites | like |
| ithy- | erect, straight |
| -itis | inflammation |
| IU | a international unit |
| IUCD | intrauterine contraceptive device |
| IUD | intrauterine device |
| IUFD | intrauterine fetal distress |
| IUP | intrauterine pregnancy |
| IV | intravenous |
| IVF | in vitro fertilization |
| IVP | intravenous pyelogram |
| IVPB | intravenous piggyback |