Online Medical Dictionary

Letter I

IBS
: Abbreviation for Irritable Bowel Syndrome.
ICU: Abbreviation for Intensive Care Unit.
Ileoscopy: Examination of the ileum through a specialized instrument.
Ileum: The last section of the small intestine, following duodenum and jejunum, and proceeding the colon.
Immune: Exempt from infection.
Immune System: The complex bodily structures and systems that serve to protect the body against disease and infections by identifying foreign antigens and pathogens and destroying or neutralizing them where possible.
Immune Tolerance: The immune system's lack of response against an antigen; occurring either naturally or by induced method.
Immunity: See Immune.
Immunization (active): The process by which the body is actively exposed to foreign molecules, usually by vaccine, in order to incite an immune response that will fortify the immune system against the antigen when exposure occurs.
Immunocompromised: An individual with an immunodeficiency.
Immunodeficiency: The immune system's inability, or impeded ability, to launch a normal immune response against an antigen or pathogen, making the body increasingly vulnerable to infectious disease. Immunodeficiency can occur as a congenital condition, primary immunodeficiency, or acquired.
Immunosuppressant: Any agent that acts to halt the immune response. Immunosuppressants can be used to treat autoimmune diseases, wherein the immune system response is undesirable, or after an organ transplant, to help counterbalance the body's natural reaction to attack the foreign tissues. Immunosupressants allow the body to become extremely vulnerable to infectious disease and cancer.
Immunotherapy: Any treatment by which the immune system is stimulated to reject and destroy harmful pathogens, such as in cancer immunotherapy, where the immune response is actively prompted to enhance its reaction against malignant tumours.
Impotence: Erectile dysfunction.
IMRT: Abbreviation for intensity modulated radiation therapy.
In situ: Located normally. In reference to a tumour, a tumour is in situ when it remains in the locale from which it originated, and does not metastasize or travel.
In vitro: From the Latin meaning within glass. Regards procedures conducted in laboratory, or in a controlled environment, outside of a live organism, such as an experiment conducted in a Petri dish.
In vivo: From the Latin meaning within the living. Any experimental procedure conducted on or in a live organism, such as testing on animals or clinical research trials.
Incidence: The amount of times in which a condition appears during a specific length of time, within a specific demographic or within a specific geographical location.
Incision: A surgical cut.
Incontinence: The inability to physically control excretions of urine from the bladder(urinary incontinence) or feces from the rectum (fecal incontinence).
Incubation Period: The length of time determined to have passed between the exposure to an infectious pathogen and the appearance of signs or symptoms associated to that exposure.
Incubator: 1. A laboratory apparatus used to sustain the environmental conditions in which a culture has been places to grow and observe. 2. The neonatal apparatus used in neonatal care units to home a premature baby until their growth and condition warrants removal from such is safe.
Indolent Lymphoma: Low-grade lymphoma. A slowly growing cancer, usually responsive to treatment.
Induced Menopause: Menopause triggered by a non-natural event, such as the surgical removal of the ovaries or damage to the ovaries by radiation therapy.
Induction Therapy: Prior to radiation therapy, chemotherapy or hormone therapy, induction is the first treatment method, or primary therapy, employed to reduce a cancer.
Infarction: The formulation of an area of dead tissue, which has resulted from a localized lack of oxygen.
Infection: The invasion of a parasitic, microscopic organism into the body, wherein the microorganism thrives and multiplies until it is destroyed by the immune system or other treatment.
Infertility: The inability to conceive after 12 consecutive months of unprotected intercourse, while the female is under the age of 34.
Inflammatory Bowel Disease: The term used to describe chronic intestinal diseases causing inflammation of the bowel, the area of the body including the large intestine and the colon. Ulcerative colitis and Crohn's disease are the most common of the inflammatory bowel diseases.
Influenza: The flu; a respiratory infection caused by the RNA viruses, affecting most mammals.
Inguinal: Regarding the groin.
Inguinal Orchiectomy: The removal of the testicle and spermatic cord when testicular cancer is thought to be present, made surgically through an incision in the abdomen and through the inguinal canal.
Innate Immunity: The natural resistance to an antigen, not aroused by vaccination or other means.
Insular Sclerosis: See Multiple Sclerosis.
Insulin: The chief hormone responsible for carbohydrate regulation and the metabolism of fats. Insulin is produced by the pancreas and controls blood glucose levels, signaling the action for cells to utilize glucose as energy and for muscles to store glycogen.
Insulin Resistance: The reduced ability of cells to respond to the insulin instruction to take up glucose, thereby raising the levels of blood glucose to adverse levels. Insulin resistance is usually incited by a poor diet, high in fats and sugars, vitamin D deficiency or other disease.
Insulinoma: An insulin-secreting tumour developing out of the beta cells of the pancreas, which though rarely malignant, can cause an excess amount of insulin in the bloodstream, lowering glucose levels to below normal and inciting hypoglycemia. Insulinoma can usually be cured surgically.
Intercurrent Disease: A disease that makes its onset while another disease is in course.
Internal Cardiac Defibrillator: See Cardiac Defibrillator.
Intersexual Genitalia: Ambiguous genitalia.
Interstitial Cystitis (IC): Disease of unknown cause, but triggering inflammation and irritation of the bladder wall, which can lead to ulcerations and bleeding and cause extreme discomfort, urgent need to urinate, and pain during urination. Pelvic floor treatments, medication and massage can be sought to subside and treat symptoms.
Interstitial Radiation Therapy: An internal radiation treatment in which radioactive material is applied directly to the cancerous tissues or tumour through needle, catheter or other sealed means.
Interval Malignancy: Cancer that rears development between yearly breast cancer mammogram screenings.
Intracerebral Hematoma: Cerebral hemorrhaging, causing the bleeding of tissue in the brain, incited by trauma, injury, or occurring spontaneously, such as in a hemorrhagic stroke. Medication, surgery and intubation can be applied toward treatment. Prognosis is dependent on the location and severity of the hemorrhage in the brain.
Intractable: Difficult to induce cessation.
Intradermal: Into or between the layers of skin, such as in an intradermal vaccine.
Intradiscal Electrothermal Therapy: A minimally invasive procedure designed to relieve lower discogenic back pain.
Intraductal Papilloma: A wart-like growth that develops benignly in the breast tissue, though sometimes puncturing a duct or causing nipples to discharge. If necessary, intraductal papillomas can be surgically removed.
Intraocular Melanoma: Cancer of the eye, developing out of the eye's pigment cells which give the eye its colour. Also termed uveal melanoma, for its effect on the uvea, which is composed of the iris, choroid and ciliary body of the eye. Treatment method includes radiation therapy and, in extreme cases, surgical removal of the cancerous eye (enucleation).
Intraocular Pressure: The pressure of fluid of the aqueous humor (the watery filling between the cornea and lens). Intraocular pressure is measured to evaluate or determine glaucoma.
Intraperitoneal Chemotherapy: Invasive cancer treatment, in which anticancer drugs are administered directly into the abdomen, as oppose to intravenously, through a thin tube. Used in the treatment of some ovarian cancers.
Intrauterine: Situated in or occurring within the uterus, such as in intrauterine insemination (IUI) or the intrauterine device (IUD), a form of birth control that is implanted in the uterus to prevent conception.
Intravenous: Into or within a vein, such as in intravenous antibiotics, in which fluid antibiotics are administered through the vein.
Intravenous Feeding: The administration of fluid nutrients, such as amino acids, glucose, lipids, vitamins and salts, through the vein. Also called parenteral alimentation or parenteral nutrition, utilized when an individual cannot otherwise consume or digest nutrients.
Invert: To turn inward or reverse the original position.
Iodine: A chemical element essential for metabolism and thyroid function. An iodine deficiency during pregnancy can result in severe mental and physical impairments in the offspring. Too much iodine can result in hyperthyroidism, and too little in hypothyroidism, which can result in general lethargy, Raynaud's condition, high cholesterol and weight gain.
Iron Deficiency Anemia: Common nutritional deficiency resulting when the body's intake of dietary iron or absorption of such is below that which is needed to form sufficient amounts of hemoglobin, the oxygen-transporting red blood cell. Iron deficiency anemia is caused largely by loss of iron during menstruation or parasitic infections, or can indicate colon cancer. Iron deficiency anemia can be treated with iron supplements, if the cause is a dietary deficiency, or with the assistance of biological aids that help the body absorb iron if the issue is iron absorption.
Irritable Bowel Syndrome: A common gastrointestinal disorder causing cramp, bloating, and alternating constipation and diarrhea. Though uncomfortable and distressing, IBS does not cause damage to the intestines or stomach, and has not been found to contribute to the development of cancer, ulcerative colitis or Crohn's disease. Cause has been linked to stress, as the lining of the colon, responsible for regulating fluid flow through the colon, is affected by the nervous system and the immune system. IBS can be treated with diet and stress management. Also called spastic colitis, nervous colon syndrome, mucus colitis, spastic bowel and/or spastic colon.
Islet Cell Carcinoma: A rare carcinoma of the pancreas, developing from endocrine cells responsible for the secretion of insulin and other hormones, which can cause the overproduction of insulin. Islet cell cancer can be treated and cured if the Islet cell tumour can be surgically removed in full and has not metastasized.
IUD: Abbreviation for intrauterine device, a method of contraception placed into the uterus through the cervix.
IV
: Abbreviation for intravenous.