Several complications are possible with HHT:
Brain AVM: About 20 percent of people with HHT will have a brain AVM. Brain AVMs can bleed, causing neurologic problems. Symptoms may include dizziness, headache, changes in vision, seizures and stroke.
Lung AVM: 15-50 percent of people with HHT will have a lung AVM. There is always a risk for rupture with this type of AVM. The risk increases during pregnancy. People with a lung AVM are also at risk for stroke or brain abscess. Other symptoms include migraines and chronic fatigue.
Liver AVM: 30-80 percent of people with HHT will have a liver AVM. Most people with liver AVMs are not treated because they don’t usually bleed or cause sudden medical problems. Rarely, later in life, liver or heart failure can occur.
Spinal AVM: Spinal AVMs are rare in HHT. They can cause pain and / or loss of feeling or function in an arm or a leg.
GI telangiectasia: About 80 percent of people with HHT have telangiectasias in their stomach and intestines; but, only 20 percent develop bleeding, most often later in life. Signs of bleeding include blood in the stool (black or bloody stools) and anemia. Anemia can cause fatigue, shortness of breath, chest pain or lightheaded feelings.
Nasal telangiectasias: Nasal telangiectasias can result in nosebleeds. Ninety-five percent of people with HHT will develop frequent nosebleeds. The chance of nosebleeds increases with age. How often and how long nosebleeds occur vary person to person. Depending on the amount of blood lost, nosebleeds can also cause anemia.
Mucocutaneous telangiectasias (hands, face, lips, mouth): 95 percent of people with HHT have telangiectasias on their hands, face, lips, or inside their mouth. The chance of developing these increases with age. The telangiectasias can bleed, but are less likely to bleed than those in the nose.