| Word Part | Definition | 
| /d | per day | 
| D&C | dilatation and curettage | 
| D&V | diarrhea & vomiting | 
| dacry/o | tears | 
| dacryoadenitis | Inflammation of the lacrimal glands (the eye’s tear-producing glands). | 
| dacryocystitis | Inflammation of the lacrimal sac. | 
| dactyl/o | fingers, toes | 
| dactylitis | Painful inflammation of the fingers or toes. | 
| dander | Fine, dry scales from the scalp. | 
| dandruff | Excessive shedding of dry scaly material from the scalp. | 
| dantrolene | Muscle relaxant drug. | 
| dark adaptation | Adjustment of the retina and pupil of the eyes under conditions of low light enabling increased sensitivity to light. | 
| DAW | dispense as written | 
| dB | decibel | 
| DBP | diastolic blood pressure | 
| dc | discontinue | 
| DDx | differential diagnosis | 
| de- | lack of, without, less, down | 
| DEA | Drug Enforcement Agency | 
| deafness | A general term for the complete loss of the ability to hear from both ears. | 
| death | Irreversible cessation of all bodily functions. | 
| debridement | A procedure used to remove dead tissue and contaminated substances from a wound, by soaking or excising. | 
| deca- | ten | 
| decapitation | Removal of the head. | 
| decay | The gradual decomposition of dead organisms after death. | 
| deceleration | A decrease in the rate of speed. | 
| deci- | one tenth | 
| decibel | A unit for comparing levels of power on a logarithmic scale. Commonly used for measuring sound. | 
| decidua | The membrane lining the wall of the uterus during pregnancy. | 
| decongestant | A substance that reduces nasal congestion. | 
| decubitus | The recumbent position. Lying on one's side. | 
| deep | Below the surface of the skin or within body cavity or limbs. | 
| deet | A common insect repellent. | 
| defamation | False written or spoken statements that are known to be false and that are damaging to the reputation of a person, group or organization. | 
| defibrillation | Use of an electronic device to give an electric shock to the heart to reestablish normal cardiac rhythm. | 
| degeneration | The gradual loss of function of a cell, tissue or organ. | 
| dehydration | The condition that results from excessive loss of water from a living organism. | 
| deja vu | A subjective feeling that a current experience is a repetition of a previous experience. | 
| delirium | A state of mental confusion that can occur due to illness, surgery or using certain medications. | 
| delirium tremens | The most severe form of alcohol withdrawal, causing confusion, irregular heart rate, and sweating. | 
| deltoid | Thick triangular muscle in the shoulder whose function is to abduct, flex, and extend the arm. | 
| delusion | A belief that is clearly false. | 
| dem/o | people, population | 
| dementia | A group of symptoms caused by brain disorder. Not a specific disease.  Causes are peripheral vascular disease, stroke, toxins, or Alzheimer's. | 
| demi | half | 
| dendrite | Short branches of the nerve cell body that receive stimuli from other neurons. | 
| dengue | An acute febrile disease transmitted by the bite of infected Aedes mosquitoes. It occurs in tropical regions and is characterized by fever, severe pain, headache and rash. | 
| denial | Refusal to admit the truth or reality of a situation or experience. | 
| dent/i | teeth | 
| dentin | The main material of teeth. It is surrounded by pulp, covered by enamel on the crown and cementum on the root. | 
| deodorant | A substance that represses or masks odors. | 
| deoxyribonucleic acid | The primary carrier of genetic information. It consists of two chains of nucleotides that are twisted into a double helix and joined by hydrogen bonds between complementary bases. | 
| dependence | The state of reliance or subservience to another person or a substance. | 
| depersonalization | A feeling of unreality concerning the self or the environment. | 
| depreciation | Decline in value of capital assets over time. | 
| depression | 1) A sunken or hollow area. 2) Mental state of feeling sad, lonely, discouraged, hopeless or dejected. | 
| deprevation | The loss or lack of something that is needed. | 
| derailment | Mental disorder marked by speech consisting of a sequence of unrelated or remotely related ideas. | 
| derivative | Something produced as a modification of another object or thought. | 
| Derm | dermatology | 
| derm/o | skin | 
| derma- | skin | 
| dermat/o | skin | 
| dermatitis | Inflammation of the skin. May be caused by allergic reaction, drugs, infection or sun exposure. | 
| dermatology | A medical specialty concerned with the structure, functions, diseases and treatment of the skin. | 
| dermis | A layer of vascularized connective tissue underneath the epidermis. Embedded in or beneath it are glands, hair follicles, nerves and lymphatic vessels. | 
| desicc/o | drying | 
| desiccation | Removal of moisture from a substance. | 
| -desis | bind, fixation | 
| desm/o | ligament | 
| desmoid tumor | A dense, fibrous neoplasm. Occurs on the abdomen, upper arms, neck and head. | 
| desmosomes | An area of contact between adjacent cells, particularly epithelia. | 
| detergent | A cleaning agent. | 
| detoxification | The removal of poisons, alcohol or drugs and their effects from a patient. | 
| detrition | Wearing away by use or friction. | 
| deviant | Pertaining to an object or person that departs from normal. Abnormal. | 
| dew point | The temperature at which water vapor in the air condenses to liquid. | 
| dextr/o | right | 
| DI | diabetes insipidus | 
| di- | two, twice, double | 
| dia- | complete, through | 
| diabetes insipidus | A hormonal condition that causes the individual to have excessive and frequent urination.  Inadequate ADH secretion. | 
| diabetes mellitus | A grouping of diseases that affect how the body uses glucose.  Type I is lack of insulin, Type II is insulin resistance. | 
| diabetic retinopathy | The most common diabetic eye disease. It occurs when blood vessels in the retina are damaged.  Leading cause of blindness in working age adults. | 
| diagnosis | The determination of the nature of a disease or condition, or the distinguishing of one disease or condition from another. | 
| diagnosis-related groups | A system for classifying patient care by relating common characteristics such as diagnosis, treatment, and age to an expected consumption of hospital resources and length of stay. | 
| dialysis | A therapeutic procedure used in patients with kidney failure for removal of harmful wastes and fluids from the blood. | 
| diaper rash | Dermatitis of the buttocks and thighs due to contact with urine or feces. | 
| diaphoresis | Profuse sweating that is artificially induced. | 
| diaphragm | The muscle sheet that that separates the thoracic cavity from the abdomen. The diaphragm's contraction and relaxation changes the volume of the thoracic cavity, aiding breathing. | 
| diarrhea | The onset of three or more loose or liquid bowel movements in a day. | 
| diastole | Part of the heart rhythm when the ventricles passively relax and refill with blood. | 
| diastolic blood pressure | Atrial blood pressure during diastole when the heart is resting.  The second number in a blood pressure reading. | 
| diathesis | Genetic predisposition to certain diseases or abnormalities. | 
| DIC | disseminated intravascular coagulation | 
| dicrotic | A heartbeat with two separate peaks. | 
| dielectric | Insulating material that can be polarized by an applied electric field. | 
| dietary fiber | Indigestible carbohydrate materials. Can be soluble or insoluble in water. | 
| dietetic | Pertaining to food and nutrition. | 
| dif- | separation, taking apart, reversal | 
| differential diagnosis | Distinguishing between two or more conditions having similar symptoms by systematic clinical comparison. | 
| differentiation | The acquisition of functions or forms different that the original. | 
| diffusion | The process of particles in gases and liquids to move from areas of high concentration to areas of lower concentration resulting in even distribution of such particles. | 
| dig | digitalis; digoxin | 
| digestion | The process of converting food into absorbable substances for metabolism and use by the body. | 
| digestive system | A group of structures, organs and glands stretching from the mouth to the anus, that breakdown food substances, absorb nutrients and remove waste. | 
| digit/o | finger, toe | 
| digitalis | Medicines that strengthen heart contraction and to slow heart rates, particularly for atrial fibrillation. | 
| digitization | The conversion of images, sounds or text into a digital form. | 
| dil | dilute; diluted | 
| dilat/o | enlarge, expand | 
| dilation | Causing the increase in the diameter of an organ, vessel or body opening. | 
| diopter | A unit of measurement of the refractive power of a lens. | 
| dioxin | Highly toxic, persistent environmental pollutant. A contaminant of a widely used herbicide. | 
| diphtheria | A bacterial infection of the upper respiratory tract that causes a thick web to form in the back of the throat.  May be fatal.  Preventable with immunization.  Can also damage heart muscle and nerves. | 
| dipl/o | double, two-sided | 
| diplegia | Paralysis involving both sides of the body. | 
| diplopia | Double vision. | 
| dips- | thirst | 
| -dipsia | thirst | 
| dipsomania | Uncontrollable, recurring craving for alcohol. | 
| dis- | twice, apart, not | 
| disc | A rounded, flat plate. | 
| discharge | To release. The substance that is released. | 
| disclosure | The revealing of information. | 
| disease | A disorder of an organ or body function.  Characterized by signs and symptoms. | 
| disinfectant | Substance that kills or inhibits harmful microorganisms. | 
| disinfection | Killing pathogens or rendering them harmless. | 
| dislocation | Displacement of a body part from its normal position. Commonly used to refer to a bone displaced from a joint. | 
| disorientation | A mentally confused state.  Loss of one's bearings. | 
| dissection | The separation of tissues for surgical reasons or for analysis. | 
| dissociation | Separation of a particular of thoughts or emotions from normal consciousness. | 
| dissolve | To disperse a solid in a solution. | 
| dist/o | distant, far | 
| distal | farthest from the origin | 
| distemper | Highly contagious and dangerous viral diseases of animals, particularly dogs. | 
| distillation | A process of separating the components of a liquid mixture by vaporization and condensation. | 
| distortion | A state of being twisted out of shape.  A defense mechanism to disguise unacceptable thoughts. | 
| diuresis | Increased excretion of urine. | 
| diuretics | Medication that promote the excretion of urine, decreasing fluids in the blood vessels and reducing blood pressure. Also known as water pills. | 
| diurnal | Daily or relating to daylight hours. | 
| diverticulitis | An inflammation in the diverticula of the intestinal tract. | 
| diverticulosis | The presence of multiple pouches, usually in the colonic or gastric wall. | 
| diverticulum | A pouch or sac developed from a tubular or saccular organ, such as the gastrointestinal tract. | 
| DJD | degenerative joint disease | 
| DKA | diabetic ketoacidosis | 
| dL | deciliter | 
| DM | diabetes mellitus | 
| DNA | deoxyribonucleic acid | 
| DNR | do not resuscitate | 
| DOA | dead on arrival | 
| DOB | date of birth | 
| DOE | dyspnea on exertion | 
| dolich/o | long | 
| dolor/o | pain | 
| dominant | Exhibiting a ruling influence.  In genetics, capable of expression when carried by only one of a pair of homologous chromosomes. | 
| donor | A human, animal or other organism that provides tissue for another body. | 
| dopamine | A central nervous system neurotransmitter. | 
| doppler effect | Changes in the observed frequency of sound, light, or radio waves due to the relative motion of source and observer. | 
| dors/o | back of body | 
| dorsal | Pertaining to the back or posterior. | 
| dorsiflexion | The movement of the ankle joint that brings the dorsal (top region) of the foot towards the shin. | 
| dorsum | top of the foot | 
| down syndrome | A congenital disorder characterized by small size, hypotonia, protruding tongue, small ears, short, broad hands and cognitive impairment. | 
| DPL | diagnostic peritoneal lavage | 
| DPT | diphtheria, pertussis, tetanus (vaccine) | 
| dr | dram | 
| drainage | The removal of fluids or discharges from the body, such as from a wound, sore, or cavity. | 
| DRE | digital rectal examination | 
| DRG | diagnosis-related group | 
| drom/o | running | 
| -drome | running | 
| dry eye syndrome | Corneal and conjunctival dryness due to deficient tear production. | 
| dry socket | An inflammation of a tooth socket, that can occur after tooth extraction, caused by the disintegration of a blood clot. | 
| DSB | drug-seeking behavior | 
| DTR | deep tendon reflex | 
| DTs | delirium tremens | 
| DUB | dysfunctional uterine bleeding | 
| duct/o | to lead | 
| duoden/o | duodenum | 
| duodenitis | Inflammation of the duodenum section of the small intestine. | 
| duodenum | The proximal (first) portion of the small intestine, extending from the pylorus to the jejunum. | 
| dur/o | hard, dura mater | 
| dura mater | The dense, leathery membrane covering and protecting the brain and spinal cord. | 
| DVT | deep vein thrombosis | 
| dwarfism | Abnormally short in stature. | 
| DWI | driving while intoxicated | 
| Dx | diagnosis | 
| dynam/o | power, strength | 
| -dynia | pain | 
| dys- | bad, painful, abnormal | 
| dysarthria | Difficulty in articulating words caused by impairment of the pharynx, larynx, tongue, or face muscles. | 
| dysentery | Acute inflammation of the intestine marked by frequent watery stools, often with blood and by pain, fever, and dehydration. | 
| dysgenesis | Defective development. | 
| dyskinesia | Involuntary muscle movements of the face, trunk, neck and extremities and difficulty with voluntary movements. Often associated with the use of certain medications. | 
| dyslexia | A common condition that affects the way the brain processes written and spoken language. | 
| dysmenorrhea | Painful cramps that can occur immediately before or during the menstrual period. | 
| dyspepsia | Impaired digestion, especially after eating. | 
| dysphagia | Difficulty in swallowing. | 
| dysphonia | Difficulty in speaking. | 
| dysplasia | Abnormal development in tissues or organs. | 
| dysplastic nevi | Unusual, benign moles that may resemble melanoma. | 
| dyspnea | Difficult or labored breathing. Can indicate heart failure or a respiratory abnormality. | 
| dyssomnia | A disorder in which normal sleep patterns are disrupted. | 
| dystocia | Difficult childbirth. | 
| dystonia | A disorder characterized by involuntary muscle contractions that cause slow repetitive movements or abnormal postures. | 
| dystrophy | Any abnormal condition caused by defective nutrition | 
| dysuria | Painful or difficult urination. |