Abscess: An infected, inflamed area in the body where pus collects.
Amblyopia: Poor vision due to non-use of an eye caused by underdevelopment of the visual pathway to the brain.
Aneurysm: A weakened dilated blood vessel that is prone to rupture (hemorrhage).
Angiogram: A test/procedure used to examine blood vessels of an organ such as the brain or lung. A small tube(catheter) is inserted into a vein or artery. A dye is then injected which highlights all the blood vessels and high-speed x-ray pictures are taken.
Angioid Streaks: Lines resembling blood vessels.
Angiogenesis: Development of blood vessels.
Angioma: Any malformation made up of blood vessels. These could be veins or a combination of arteries and veins (arteriovenous malformations or AVMs).
Anticonvulsant: Any medication that counteracts seizures.
Arterial Blood Gases (ABG): As part of the testing for PAVMs, blood is taken from an artery in the wrist to measure the oxygen level.
Arteriogram: See angiogram
Arteriovenous Malformation: An abnormal, direct connection (like a short circuit)between an artery and a vein.
Asymptomatic: Having no obvious symptoms.
Autosomal Dominant: A genetic term describing a disorder that affects men and women equally and has a 50% chance to be passed to each of ones offspring.
AVM: see arteriovenous malformation.