Webster's New World Medical Dictionary

ductal carcinoma of the breast, infiltrating
See 
carcinoma of the breast, infiltrating ductal.
ductus
See 
duct.
ductus arteriosus
A short vessel through which
blood headed from the heart via the pulmonary
artery to the lungs is shunted before birth. This
blood is shunted away from the lungs and returned
to the aorta. When the shunt is open, it is said to be
patent. A patent ductus arteriosus (PDA) usually
closes at or shortly after birth, and blood is permit-
ted from that moment on to course freely to the
lungs. If the ductus stays open, flow reverses, and
blood from the aorta is shunted into the pulmonary
artery and recirculated through the lungs. The PDA
may close later on its own, or it may need to be lig-
ated (tied off) surgically.
due date
The estimated calendar date when a
baby is due to be born. Also called the estimated
date of confinement (EDC).
dumping syndrome
A group of symptoms,
including cramps, nausea, diarrhea, and dizziness,
that occur when food or liquid enters the small
intestine too rapidly.
duodenal ulcer
A crater (ulcer) in the lining of
the beginning of the small intestine (duodenum).
Ulcer formation is caused by infection with
Helicobacter pylori. Other factors predisposing a
person to ulcers include anti-inflammatory medica-
tions and cigarette smoking. Ulcer pain may not
correlate with the presence or severity of ulceration.
Diagnosis is made with barium X-ray or endoscopy.
Complications of ulcers include bleeding, perfora-
tion, and blockage. Treatment involves using antibi-
otics to eradicate H. pylori, eliminating risk factors,
and preventing complications.
duodenitis
Inflammation of the duodenum, the
first part of the small intestine.