Dictionary

dilation See dilatation.

dilation, pupil 1 A type of eye examination that enables an eye-care professional to see more of the retina, the light-sensitive layer of tissue at the back of the eye. Dilating the pupil permits the retina to be examined for signs of disease. To dilate the pupil, drops are placed into the eye. 2 A…

dilation and curettage A minor operation in which the cervix is expanded (dilatated) enough to permit the cervical canal and uterine lining to be scraped with a spoon-shaped instrument called a curette (curettage). Abbreviated D & C. D & C is normally used to remove abnormal material from the uterus, such as unexpelled placental material…

dilator A device used to stretch or enlarge an opening. Patients with scarring of the esophagus can require a dilator procedure to open the esophagus for adequate passage of food and fluids.

diphtheria An acute infectious upper respiratory tract disease that affects the throat. It is caused by the bacteria Corynebacterium diphtheriae. Symptoms include sore throat and mild fever at first. As the disease progresses, a membranous substance forms in the throat that makes it difficult to breathe and swallow. Diphtheria can be deadly. It is one…

diagnosis, differential See differential diagnosis.

dialysis The process of cleansing the blood by passing it through a special machine. Dialysis is necessary when the kidneys are not able to filter the blood. It gives patients with kidney failure a chance to live productive lives. There are two types of dialysis: hemodialysis and peritoneal dialysis. A hemodialysis session generally takes about…

dialysis, peritoneal A dialysis technique that uses the patient’s own body tissues inside the belly (abdominal cavity) as a filter. The intestines lie in the abdominal cavity, the space between the abdominal wall and the spine. A plastic tube called a dialysis catheter is placed through the abdominal wall and into the abdominal cavity. A…

dialysis machine A machine used in dialysis that filters a patient’s blood to remove excess water and waste products when the kidneys are damaged, dysfunctional, or missing. The dialysis machine itself can be thought of as an artificial kidney. Inside, it consists of more plastic tubing that carries the removed blood to the dialyser, a…

diaper rash An inflammatory reaction localized to the area of skin usually covered by the diaper. It can have many causes, including infections (yeast, bacterial, or viral), friction irritation, chemical allergies (perfumes, soaps), sweat, decomposed urine, and plugged sweat glands. Most diaper rash problems can be solved by cleansing the skin with nonperfumed, gentle products;…

diaphragm 1 The muscle that separates the chest (thoracic) cavity from the abdomen. Contraction of the diaphragm helps to expand the lungs when one breathes in air. 2 A specially fitted contraceptive device that covers the cervix to prevent the entry of sperm. For greatest effectiveness, a diaphragm is used with spermicidal gel or cream….

diaphragm pacing A procedure to help patients with spinal cord injuries to breathe. Their breathing is helped by setting the respiratory rate by electrical stimulation (pacing) of the phrenic nerve using electrodes surgically implanted into the diaphragm muscle that is innervated by the nerve.