Online Medical Dictionary

Letter D

Inflammation of the tear-producing lacrimal gland.
The swelling of fingers and/or toes.
Dietary Approaches to Stop Hypertension (DASH Diet)
Eating plan designed and allocated to patients with aim to reduce blood pressure.
de Musset Sign
A rhythmic nodding of the head synchronized with the heart beat. May be indicative of aortic insufficiency.
To enfeeble or impair strength.
To remove a tumor, or a quantity of dead tissue, from the body by laser, irradiation, chemotherapy or surgery.
An agent that acts to shrink the swollen membranes of the nose, enabling easier breathing patterns.
Removal of a segment or all of the outer surface of any organ.
The use of electrical impulses by which to normalize, or restart, heart rhythms.
An electronic device used to restart or to correct abnormal heart rhythms by delivering brief, measured electrical currents to the heart muscle, or through the chest wall.
Degeneration, macular
A progressive disease that works to destroy the central portion of the retina, the macula, impairing central vision.
Degenerative Arthritis
Arthritis caused by the inflammation and breakdown of the cartilage located between joints. Also called osteoarthritis or degenerative joint disease.
A profound confusion aroused in quick onset, in which the individual may become unable to interact normally, to concentrate or to speak coherently.
The large, triangular muscle stretching from the collarbone to the humerus of the upper arm, covering the shoulder.
Delusional Parasitosis
The false belief that one's body is infested by parasites or other tiny organisms.
A severe loss of cognitive capabilities, causing profuse confusion, most common in geriatric populations.
The loss of nerve supply. Denervation has many causes: disease, such as polio, where the denervation of muscle fibers is incited by the death of motor neurons; chemical; physical injury; or interruption, such as in the body's response to provide pain relief.
An acute mosquito-borne viral illness, mainly virulent in tropical regions, known to cause epidemics and can be life threatening. Also called Dengue hemorrhagic fever.
Hemoglobin without oxygen.
The loss of pigmentation, that which gives colour, which can occur in the skin, mucous membranes, hair or retina.
Regarding the skin.
Inflammation of the skin, caused by contact with an irritating substance or an allergen, the two types of which are eczema and noneczematous, or occupational.
A small, slowly growing, common benign skin tumor, most often found on the legs. Also termed fibrous histiocytoma.
A doctor specialized in the diagnosis of skin conditions and their treatment.
The branch of medicine concerned with the diagnosis, treatment, and prevention of conditions or diseases involving the skin.
A chronic inflammatory myopathic disease. When the inflammation of the muscle occurs in absence of the skin disease, the condition is termed polymyositis.
A diagnostic technique testing for melanoma and other lesions on the skin. Also called dermoscopy, epiluminescence microscopy and surface microscopy.
The inner layer of cells composing the skin, containing blood and lymph vessels, hair follicles, and sweat glands.
Any disease of the skin. Also called dermatopathy.
Desmoid Tumor
A benign, soft tissue tumor occurring mainly in young adults, usually in the limbs and sometimes in the abdomen or throat, which does not metastasize.
Deviated Septum
A condition in which the nasal septum, the wall that separates the air passages on either side of the nose, is displaced to one side of the face, usually as a result of nose trauma or injury.
The congenital reversal of the heart's location to the chest's right side. Dextrocardia is one effect of the congenital Kartagener's syndrome.
Diabetes Mellitus Type 1
Diabetes resulting from the autoimmune destruction of the insulin-producing beta cells found in the pancreas. The lack of insulin causes increased blood glucose, resulting in frequent urination, thirst, hunger, and weight loss. Diabetes type 1 must be treated with insulin supplement, or else becomes fatal.
Diabetes Mellitus Type 2
Diabetes resulting from a metabolic disorder marked by insulin deficiency, causing high blood glucose. Diabetes type 2 can usually be treated with a monitored diet and exercise, though medication may be required in some cases.
Diabetic Coma
A diabetic individual who becomes unconscious due to: 1. severe hypoglycemia, wherein blood glucose levels fall significantly and are not halted in time with consumption of carbohydrates; 2. diabetic ketoacidosis, wherein an individual falls unconscious after profuse vomiting and hyperventilation, due to a combination of severe hyperglycemia, dehydration, shock and exhaustion; or 3. nonketotic hyperosmolar coma, accompanied by severe dehydration, more common in individuals with type 2 diabetes.
Diabetic Shock
Hypoglycemia, or low blood glucose levels, causing fatigue, dizziness or fainting, flushing of the skin, or vomiting. Immediate administration of glucagon can reverse the effects of insulin abundance.
The identification of a condition or illness to which an individual has been found to have.
The treatment by which the functions of injured or diseased kidneys, those experiencing renal failure, are attempted to be replaced, providing waste and fluid removal, through hemodialysis or peritoneal dialysis.
Diaphragm Pacing
A procedure, also known as phrenic nerve pacing, by which patients with spinal cord injuries are assisted in breathing with the assistance of electrical impulses transmitted in rhythmic application to the diaphragm.
Referring to the period of time wherein the heart is relaxed and dilated (referring to diastole).
Diastrophic Dysplasia
A genetic skeletal disorder affecting bone and cartilage development, characterized by a significantly short stature.
See Cauterization.
Differentiated Cancer
Cancer composed of mature cells that look like the surrounding cells of the tissue in which they are dividing. Differentiated cancers tend to have a better prognosis than undifferentiated cancers composed of primitive-looking, immature cells.
The process by which cells become increasingly specialized.
Differentiation Therapy
A cancer treatment approach that attempts to force malignant cells to resume the normal cell maturation cycle, based on the concept that malignant cells are just normal cells that were arrested while still immature, thus they lack the ability to grow normally, and so they divide and multiply with abnormal and dangerous speed. Differentiation therapy does not destroy cancerous cells but does provide a less toxic alternative to, for example, chemotherapy.
Digestive System
The system composed of the organs responsible for taking in food, utilizing the necessary components of it, and secreting its waste. These organs include the salivary glands, mouth, esophagus, stomach, liver, gallbladder, pancreas, small intestine, colon and rectum.
To expand or enlarge.
The process of enlarging or expanding.
To enlarge.
An acute infectious disease caused by the bacteria corynebacterium diphtheriae, usually affecting the upper respiratory tract and throat.
Excessive thirst that may occur when the body is dehydrated for any variety of reasons.
Disease Surveillance
The continual, systematic provision, collection and analysis of disease and health information with the aim of establishing preventative measures and wide-scale disease awareness, particularly where conditions are infecting.
The act of taking apart or disassembling tissue in order to determine its function, internal structure, or the working order of its components.
Disseminated Sclerosis
See Multiple Sclerosis.
Having an extra row of eyelashes, which emerge from the meibomian glands, sometimes protruding into the cornea and causing corneal abrasions.
The increased formation of urine by the kidney (polyuria).
That which increases the formation of urine by the kidney.
Occurring during daytime. Opposite of nocturnal.
A common digestive disease of the large intestine, developing when diverticula (diverticulosis caused pouches formed along the wall of the colon) become inflamed.
The condition in which diverticula are formed in the colon. Diverticula are small outpocketings of mucosa developed out of a weak colon wall.
Dizygotic Twins
Fraternal twins, resulting when two ova are fertilized by two unique sperm cells and implant on the uterus wall at the same time.
Deoxyribonucleic acid. DNA contains two anti-parallel, long polymers, attached to which are bases, the sequence of which encodes genetic or structural information.
A person who donates tissue or organ, while still living or posthumously, toward a recipient in need of such.
A catecholamine neurotransmitter produced in many areas of the brain. Dopamine can be administered intravenously as a medication, acting on the sympathetic nervous system and producing effects such as increased heart rate and blood pressure. L-Dopa, the precursor of dopamine, is used in the treatment of Parkinson disease.
Doppler Ultrasound
Also called Doppler echocardiography or Doppler sonography, a type of ultrasound technology that examines the heart and uses the Doppler effect, which observes changes in frequency waves in regard to movement, to measure the direction and speed of blood flow.
An abnormal and persistent fear of fur.
Regarding the back or posterior. Opposite of ventral, pertaining to the front.
Latin for the word back; posterior.
Double Helix
The DNA structure, composed of two spiraling strands.
Term used to describe hypermobility or hyperflexibility, a joint that is more flexible than normal.
Down Syndrome
A common chromosomal disorder caused by the partial or full formation of an extra chromosome, trisomy G or trisomy 21. Down syndrome causes cognitive impairment and retardation in physical development, ranging from mid to moderate mental disability.
Dressler Syndrome
A form of pericarditis, inflammation of the pericardium, the lining of the heart, brought on by the occurrence of a heart attack or other trauma incurred by the heart.
Duchenne Muscular Dystrophy
A form of muscular dystrophy caused by a mutation on the X chromosome, preventing the production of dystrophin, an important protein in muscle development, causing rapid muscle degeneration. Duchenne Muscular Dystrophy usually appears in boys around the age of two, usually decreasing life span to just over 20 years. As of yet DMD is incurable.
Inflammation of the duodenum.
The first segment of the small intestine extending from the pylorus, located at the bottom of the stomach, to the jejunum, the second segment of the small intestine. The duodenum tissues are a common site for the development of peptic ulcers.
Dura Mater
The tough, fibrous, and outermost layer of the three meninges insulating the brain and the spinal cord and functioning to retain the cerebrospinal fluid.
Dx or DX
Abbreviation for medical diagnosis.
Abbreviation for dual X-ray absorptometry, a technique used to conduct bone scans and to measure bone mineral density.
DXA Bone Scan
See DXA.
A speech disorder marked by slurred, slow, and difficult to understand orations, caused by neurological injury.
A specific learning disability affecting an individual's ability to comprehend and engage in mathematics, in some cases the result of brain injury.
Inflammation of the colon and intestine caused by bacterial, parasitic or viral infection, most commonly an amoeba, inducing severe diarrhea, abdominal pain and fever. Dysentery can be fatal if left untreated.
A fine motor skill deficiency impeding one's ability to write, not in anyway a result of intellectual impairment, nor does it have effect on the ability to read or to comprehend language.
A general definition used to describe an impairment of one's ability to read.
The presence of an abnormal amount of lipids (cholesterol and fat) in the blood due to a disorder of in lipoprotein metabolism, often the result of poor diet.
Dysmorphic Feature
An abnormally formed corporal characteristic.
A condition marked by chronic upper abdominal pain, a feeling of satiety when little is eaten, bloating and heartburn, often as a result of gastritis, gastro-oesophageal reflux disease or, in some cases, peptic ulcer disease. Dyspepsia should prompt further medical investigation.
Difficulty in swallowing resulting from problems in muscle or nerve impulse control, common in individuals following a stroke.
A partial acquired speech disorder, in which there is impairment of some modality of language, which could include the inability to speak, write or sign, or to comprehend spoken or written language. Total language impairment is defined as aphasia, though dysphasia is also commonly grouped into that term.
An vocal impairment, often resulting in hoarseness.
Abnormal formation.
Difficult and/or labored breathing. Dyspnea can be a symptom of a serious disease of the lungs or heart.
Impaired or painful function of any organ.
Painful or difficult urination, most commonly caused by inflammation of the bladder or kidneys resulting from a bacterial infection of the urinary tract.