Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer ). See the entire definition of Abnormal
Adenoma: A benign tumor that arises in or resembles glandular tissue. If it becomes cancerous, it is called an adenocarcinoma.
Aggressive: In oncology, quickly growing, tending to spread rapidly. As, for example, an aggressive tumor. See the entire definition of Aggressive
Anesthetic: A substance that causes lack of feeling or awareness. A local anesthetic causes loss of feeling in a part of the body. A general anesthetic puts the person to sleep.
Aspirate: To suck in. A patient may aspirate for example by accidentally drawing material from the stomach into the lungs. A doctor can aspirate a joint.
Aspiration: Removal of a sample of fluid and cells through a needle. Aspiration also refers to the accidental sucking in of food particles or fluids into the lungs.
Autoimmune: Pertaining to autoimmunity, a misdirected immune response that occurs when the immune system goes awry and attacks the body itself. See the entire definition of Autoimmune
Autoimmune disease: An illness that occurs when the body tissues are attacked by its own immune system . The immune system is a complex organization within the body that is designed normally to "seek and destroy" invaders of the body, including infectious agents. Patients with autoimmune diseases frequently have unusual antibodies circulating in their blood that target their own body tissues. See the entire definition of Autoimmune disease
Autoimmune thyroiditis: See: Hashimoto thyroiditis.
Benign: Not cancer. Not malignant . A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place). See the entire definition of Benign
Biopsy: The removal of a sample of tissue for purposes of diagnosis. (Many definitions of "biopsy" stipulate that the sample of tissue is removed for examination under a microscope. This may or may not be the case. The diagnosis may be achieved by other means such as by analysis of chromosomes or genes.) See the entire definition of Biopsy
Blood: The familiar red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. The blood is transported throughout the body by the circulatory system. Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.
Breast : The breast refers to the front of the chest or, more specifically, to the mammary gland. The mammary gland is a milk producing gland. It is composed largely of fat. Within the mammary gland is a complex network of branching ducts. These ducts exit from sac-like structures called lobules, which can produce milk in females. The ducts exit the breast at the nipple. See the entire definition of Breast
Bridge: A set of one or more false teeth supported by a metal framework, used to replace one or more missing teeth. See the entire definition of Bridge
Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread). See the entire definition of Cancer
Carcinoma: Cancer that begins in the skin or in tissues that line or cover body organs. For example, carcinoma can arise in the breast , colon, liver, lung, prostate, and stomach. See the entire definition of Carcinoma
Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane . See the entire definition of Cell
Compress: 1. As a noun, a cloth or another material applied under pressure to an area of the skin and held in place for a period of time. A compress can be any temperature (cold, luke warm, or hot) and it can be dry or wet. It may also be impregnated with medication or, in traditional medicine, an herbal remedy. Most compresses are used to relieve inflammation. 2. As a verb, to squeeze or press together. An injury can compress the spinal cord.
Compression: 1. The act of pressing together. As in a compression fracture, nerve compression, or spinal cord compression. 2. To shorten in time. In embryology, there may be compression of development with some stages even omitted.
Computerized tomography: Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them in pictures. See the entire definition of Computerized tomography
Curable: Amenable to a cure, capable of being cured, to being healed and made well. Most skin cancers, fortunately, are curable. From the word cure, from the Latin cura meaning care, concern or attention.
Cyst: A cyst is an abnormal, closed sac-like structure within a tissue that contains a liquid, gaseous, or semisolid substance. A cyst can occur anywhere in the body and can vary in size. The outer, or capsular, portion of a cyst is termed the cyst wall.
Diagnosis: 1 The nature of a disease ; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies . 3 The identification of any problem. The diagnosis was a plugged IV. See the entire definition of Diagnosis
Disease: Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.
Ear: The hearing organ. There are three sections of the ear, according to the anatomy textbooks. They are the outer ear (the part we see along the sides of our head behind the temples), the middle ear, and the inner ear. But in terms of function, the ear has four parts: those three and the brain. Hearing thus involves all parts of the ear as well as the auditory cortex of the brain. The external ear helps concentrate the vibrations of air on the ear drum and make it vibrate. These vibrations are transmitted by a chain of little bones in the middle ear to the inner ear. There they stimulate the fibers of the auditory nerve to transmit impulses to the brain. See the entire definition of Ear
Endocrine: Pertaining to hormones and the glands that make and secrete them into the bloodstream through which they travel to affect distant organs. The endocrine sites include the hypothalamus, pituitary gland, pineal gland, thyroid, parathyroids, heart (which makes atrial-natriuretic peptide), the stomach and intestines, islets of Langerhans in the pancreas, the adrenal glands, the kidney (which makes renin, erythropoietin, and calcitriol), fat cells (which make leptin). the testes, the ovarian follicle (estrogens) and the corpus luteum in the ovary). Endocrine is as opposed to exocrine. (The exocrine glands include the salivary glands, sweat glands and glands within the gastrointestinal tract.)
Esophagus: The tube that connects the pharynx (throat) with the stomach. The esophagus lies between the trachea (windpipe) and the spine. It passes down the neck, pierces the diaphragm just to the left of the midline, and joins the cardiac (upper) end of the stomach. In an adult, the esophagus is about 25 centimeters (10 inches) long. When a person swallows, the muscular walls of the esophagus contract to push food down into the stomach. Glands in the lining of the esophagus produce mucus, which keeps the passageway moist and facilitates swallowing. Also known as the gullet or swallowing tube. From the Greek oisophagos, from oisein meaning to bear or carry + phagein, to eat.
Fine needle aspiration: The use of a thin needle to withdraw material from the body. For example, this method is commonly used to determine whether a nodule in the thyroid gland is benign or malignant. A fine gauge needle is placed into the nodule and a drop of blood is withdrawn. The cells are studied under the microscope by an pathologist. See the entire definition of Fine needle aspiration
Geiger counter: The most commonly used portable radiation detection and measuring instrument, consisting of a gas-filled tube containing electrodes, between which an electrical voltage but no current flows. When ionizing radiation passes through the tube, a short, intense pulse of current passes from the negative electrode to the positive electrode and is measured or counted. The number of pulses per second measures the intensity of the radiation field. Geiger counters are highly sensitive to beta particles but relatively insensitive to gamma rays and x-rays.
Genes: The basic biological units of heredity . Segments of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Genes
Gland: 1. A group of cells that secrete a substance for use in the body. For example, the thyroid gland. 2. A group of cells that removes materials from the circulation. For example, a lymph gland.
Goiter: Enlargement of the thyroid gland . See the entire definition of Goiter
Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest. See the entire definition of Heart
Heart failure : Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling ( edema ), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart. See the entire definition of Heart failure
Heart rate: The number of heart beats per unit time, usually per minute. The heart rate is based on the number of contractions of the ventricles (the lower chambers of the heart). The heart rate may be too fast ( tachycardia ) or too slow ( bradycardia ). The pulse is bulge of an artery from the wave of blood coursing through the blood vessel as a result of the heart beat. The pulse is often taken at the wrist to estimate the heart rate. See the entire definition of Heart rate
Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. See the entire definition of Hormone
Hypothyroid: Deficiency of thyroid hormone which is normally made by the thyroid gland which is located in the front of the neck:
Immune: Protected against infection. The Latin immunis means free, exempt.
Immune system: A complex system that is responsible for distinguishing us from everything foreign to us, and for protecting us against infections and foreign substances. The immune system works to seek and kill invaders. See the entire definition of Immune system
Indication: 1. In medicine, a condition which makes a particular treatment or procedure advisable. CML (chronic myeloid leukemia) is an indication for the use of Gleevec (imatinib mesylate). 2. A sign or a circumstance which points to or shows the cause, pathology, treatment, or outcome of an attack of disease. The presence of the Philadelphia chromosome in peripheral blood cells is an indication of a relapse in CML.
Iodine: An essential element in the diet used by the thyroid gland to make thyroid hormones . See the entire definition of Iodine
Isotope: A form of a chemical element with the same atomic number as another element but having a different atomic mass. Isotopes are used in a number of medical tests. See the entire definition of Isotope
Jaw: The bones below the mouth (the mandible) and the bone above the mouth just above the mouth (the maxilla). The word jaw comes from the Anglo-Saxon ceowan meaning to chew. See the entire definition of Jaw
Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination. See the entire definition of Kidney
Larynx: The larynx is the portion of the breathing, or respiratory, tract containing the vocal cords which produce vocal sound. It is located between the pharynx and the trachea. The larynx, also called the voice box, is a 2-inch-long, tube-shaped organ in the neck. See the entire definition of Larynx
Lymph: An almost colorless fluid that travels through vessels called lymphatics in the lymphatic system and carries cells that help fight infection and disease.
Lymphoma: Tumor of the lymphoid tissue. Diagnosis is by biopsy. Treatment may be chemotherapy, radiation, surgery, or medication, depending on the age of the patient and type of tumor.
Magnetic resonance imaging : A special radiology technique designed to image internal structures of the body using magnetism, radio waves, and a computer to produce the images of body structures. In magnetic resonance imaging (MRI), the scanner is a tube surrounded by a giant circular magnet. The patient is placed on a moveable bed that is inserted into the magnet. The magnet creates a strong magnetic field that aligns the protons of hydrogen atoms, which are then exposed to a beam of radio waves. This spins the various protons of the body, and they produce a faint signal that is detected by the receiver portion of the MRI scanner. A computer processes the receiver information, and an image is produced. The image and resolution is quite detailed and can detect tiny changes of structures within the body, particularly in the soft tissue, brain and spinal cord, abdomen and joints. See the entire definition of Magnetic resonance imaging
Malignant: 1. Tending to be severe and become progressively worse, as in malignant hypertension. 2. In regard to a tumor, having the properties of a malignancy that can invade and destroy nearby tissue and that may spread (metastasize) to other parts of the body. See the entire definition of Malignant
Metastasize: The spread from one part of the body to another. When cancer cells metastasize and cause secondary tumors, the cells in the metastatic tumor are like those in the original cancer. See the entire definition of Metastasize
Microscope: An optical instrument that augments the power of the eye to see small objects. The name microscope was coined by Johannes Faber (1574-1629) who in 1628 borrowed from the Greek to combined micro-, small with skopein, to view. Although the first microscopes were simple microscopes, most (if not all) optical microscopes today are compound microscopes.
MRI: Abbreviation and nickname for magnetic resonance imaging. For more information, see: Magnetic Resonance Imaging; Paul C. Lauterbur; Peter Mansfield.
Neck: The part of the body joining the head to the shoulders. Also, any narrow or constricted part of a bone or organ that joins its parts as, for example, the neck of the femur bone. See the entire definition of Neck
Nodule: A small solid collection of tissue, a nodule is palpable (can be felt). It may range in size from greater than 1.0 cm (3/8 inch) to somewhat less than 2 cm (13/16 inch) in diameter. A nodule may be present in the epidermis, dermis or subcutis (at any level in the skin). See the entire definition of Nodule
Osteoporosis: Thinning of the bones with reduction in bone mass due to depletion of calcium and bone protein . Osteoporosis predisposes a person to fractures, which are often slow to heal and heal poorly. It is more common in older adults, particularly post-menopausal women; in patients on steroids; and in those who take steroidal drugs. Unchecked osteoporosis can lead to changes in posture , physical abnormality (particularly the form of hunched back known colloquially as " dowager's hump "), and decreased mobility. See the entire definition of Osteoporosis
Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia . Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors. See the entire definition of Pain
Pathologist: A doctor who identifies diseases by studying cells and tissues under a microscope.
Prevalence: The proportion of individuals in a population having a disease. Prevalence is a statistical concept referring to the number of cases of a disease that are present in a particular population at a given time. See the entire definition of Prevalence
Primary: First or foremost in time or development. The primary teeth (the baby teeth) are those that come first. Primary may also refer to symptoms or a disease to which others are secondary. See the entire definition of Primary
Probability: The likelihood that something will happen. For example, a probability of less than .05 indicates that the probability of something occurring by chance alone is less than 5 in 100, or 5 percent. This level of probability is usually taken as the level of biologic significance, so a higher incidence may be considered meaningful. The abbreviation for probability is P.
Prognosis: 1. The expected course of a disease . 2. The patient's chance of recovery. The prognosis predicts the outcome of a disease and therefore the future for the patient . His prognosis is grim, for example, while hers is good. See the entire definition of Prognosis
Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein. See the entire definition of Protein
Radiation: 1. Rays of energy. Gamma rays and X-rays are two of the types of energy waves often used in medicine. 2. The use of energy waves to diagnose or treat disease. See also: Irradiation.
Radioactive: Emitting energy waves due to decaying atomic nuclei. Radioactive substances are used in medicine as tracers for diagnosis, and in treatment to kill cancerous cells. See the entire definition of Radioactive
Radioactive iodine: An isotope of the chemical element iodine that is radioactive . Radioactive iodine is used in diagnostic tests as well as in radiotherapy of an hyperactive thyroid gland (hyperthyroidism), most often due to Graves disease . See the entire definition of Radioactive iodine
Radionuclide: An unstable form of a chemical element that radioactively decays, resulting in the emission of nuclear radiation. Also called a radioisotope.
Rest: 1. Repose. Relaxation. 2. A fragment of embryonic tissue that has been retained after the period of embryonic development. Also called an embryonic rest.
Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office. See the entire definition of Surgery
Therapy: The treatment of disease . See the entire definition of Therapy
Thyroglobulin: A protein found in the thyroid gland. Some thyroglobulin can be found in the blood, and this amount may be measured after thyroid surgery to determine whether thyroid cancer has recurred. Thyroglobulin derived from pig thyroid glands is sometimes given to treat thyroid dysfunction. Abbreviated Tg.
Thyroid: 1. The thyroid gland. Also, pertaining to the thyroid gland. 2. A preparation of the thyroid gland used to treat hypothyroidism. 3. Shaped like a shield. (The thyroid gland was so-named by Thomas Wharton in 1656 because it was shaped like an ancient Greek shield.)
Thyroid cancer : Cancer of the gland in front of the neck that normally produces thyroid hormone which is important to the normal regulation of the metabolism of the body. There are 4 major types of thyroid cancer -- papillary, follicular, medullary, and anaplastic. The most common symptom of thyroid cancer is a lump, or nodule, that can be felt in the neck. The only certain way to tell whether a thyroid lump is cancer is by examining the thyroid tissue, obtained using a needle or surgery to obtain a biopsy. See the entire definition of Thyroid cancer
Thyroid gland: A gland that makes and stores hormones that help regulate the heart rate, blood pressure, body temperature, and the rate at which food is converted into energy. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions ( metabolism ) in the body. Thyroid hormones also help children grow and develop. See the entire definition of Thyroid gland
Thyroid hormone: A chemical substance made by the thyroid gland for export into the bloodstream. The thyroid gland needs iodine to make thyroid hormones. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3). See the entire definition of Thyroid hormone
Thyroid hormones: Chemical substances made by the thyroid gland, which is located in the front of the neck. This gland uses iodine to make thyroid hormones, which are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions (metabolism), and are involved in the circadian rhythms that govern sleep , among other essential functions. See the entire definition of Thyroid hormones
Thyroid stimulating hormone: A hormone produced by the pituitary gland at the base of the brain in response to signals from the hypothalamus gland in the brain. Thyroid stimulating hormone (TSH) promotes the growth of the thyroid gland in the neck and stimulates it to produce more thyroid hormones . When there is an excessive amount of thyroid hormones, the pituitary gland stops producing TSH, reducing thyroid hormone production. This mechanism maintains a relatively constant level of thyroid hormones circulating in the blood. See the entire definition of Thyroid stimulating hormone
Thyroiditis : Inflammation of the thyroid gland which is located in front of the neck: See the entire definition of Thyroiditis
Tissue: A tissue in medicine is not like a piece of tissue paper. It is a broad term that is applied to any group of cells that perform specific functions. A tissue in medicine need not form a layer. Thus, - The bone marrow is a tissue;
- Connective tissue consists of cells that make up fibers in the framework supporting other body tissues; and
- Lymphoid tissue is the part of the body's immune system that helps protect it from bacteria and other foreign entities.
Tomography: The process for generating a tomogram , a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process. See the entire definition of Tomography
Trachea: A tube-like portion of the breathing or "respiratory" tract that connects the "voice box" (larynx) with the bronchial parts of the lungs. See the entire definition of Trachea
TSH: Stands for thyroid stimulating hormone, a hormone produced by the pituitary gland at the base of the brain in response to signals from the hypothalamus gland in the brain. TSH promotes the growth of the thyroid gland in the neck and stimulates it to produce more thyroid hormones . When there is an excessive amount of thyroid hormones, the pituitary gland stops producing TSH, reducing thyroid hormone production. This mechanism maintains a relatively constant level of thyroid hormones circulating in the blood. See the entire definition of TSH
Ultrasound : High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine a fetus during pregnancy. There is no convincing evidence for any danger from ultrasound during pregnancy. See the entire definition of Ultrasound
Voice box:The voice box, or larynx, is the portion of the respiratory (breathing) tract containing the vocal cords which produce sound. It is located between the pharynx and the trachea. The larynx, also called the voice box, is a 2-inch-long, tube-shaped organ in the neck. See the entire definition of Voice box
Windpipe: The trachea, a tube-like portion of the respiratory (breathing) tract that connects the larynx (the voicebox) with the bronchial parts of the lungs. See the entire definition of Windpipe
- levothyroxine sodium, Synthroid, Levoxyl, Levothroid, Unithroid - Learn more about Levothyroxine Sodium (Synthroid, Levoxyl, Levothroid, Unithroid), including a description, generic and brand names, drug class and mechanism, preparations, storage, reasons for prescription, dosing, drug interactions, effect on pregnancy and nursing mothers, and common side effects.
- CT Scan (Computerized Axial Tomography) - CT Scan (Computerized Axial Tomography, CAT scan) is a procedure that assists in diagnosing tumors, fractures, bony structures, and infections in the organs and tissues of the body.
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