Thursday, June 6, 2013

June is HHT Awareness Month

Hereditary Hemorrhagic Telangiectasia (HHT) is a genetic disorder that causes abnormalities of blood vessels, usually resulting in excessive bleeding (known as hemorrhaging). In order to understand HHT, you must first understand the way blood is pumped to and from the heart. Blood vessels are hollow structures that transport blood throughout the body.
There are two types of blood vessels: arteries and veins. Arteries carry blood under high pressure away from the heart to all other areas of the body. Blood then passes through capillaries, where oxygen, nutrients and waste products can be exchanged. Veins carry blood that should be under low pressure back to the heart. An artery does not usually connect directly to a vein.
A person with HHT has a tendency to form blood vessels that lack capillaries between the arteries and veins, meaning that arterial blood under high pressure flows directly into a vein without first going through the very small capillaries. The site of this abnormal connection tends to be fragile and can rupture and result in bleeding.
This type of abnormal blood vessel is called a telangiectasia if it involves small blood vessels. It is called an arteriovenous malformation (AVM) if it involves large blood vessels. Telangiectases usually occur on the surface of the body, such as the skin and the mucous membranes that line the nose and the gastrointestinal tract. AVMs are found in the lungs, liver and central nervous system. Read more...

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