National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder of the blood vessels that can cause excessive bleeding. People with HHT can develop abnormal blood vessels called arteriovenous malformations (AVMs) in several areas of the body. AVMs on the skin are called telangiectasias. AVMs can also develop in other parts of the body, including the brain, lungs, liver, or intestines.[1] HHT is caused by a mutation in one of several genes, including ACVRL1, ENG, SMAD4, and GDF2. Changes in at least other two unknown genes are also suspected of causing HHT in some people.[2] HHT is inherited in an autosomal dominant pattern, which means a person only needs to inherit one copy of the changed gene to have HHT.[3] While there is no cure for HHT, treatment is symptomatic and supportive, with a focus on controlling bleeding and preventing medical complications, either through surgery or medication.[1]
Last updated: 10/13/2017

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Epistaxis
Bloody nose
Frequent nosebleeds
Nose bleed
Nose bleeding
Nosebleed
[ more ] 		0000421
Telangiectasia of the skin 0100585
30%-79% of people have these symptoms
Cavernous hemangioma
Collection of dilated blood vessels that forms mass
0001048
Cholecystitis
Gallbladder inflammation
0001082
Microcytic anemia 0001935
Migraine
Intermittent migraine headaches
Migraine headaches
Migraine headache
[ more ] 		0002076
Portal hypertension 0001409
Spontaneous hematomas 0007420
Visceral angiomatosis 0100761
5%-29% of people have these symptoms
Amblyopia
Lazy eye
Wandering eye
[ more ] 		0000646
Cerebral hemorrhage
Bleeding in brain
0001342
Cholelithiasis
Gallstones
0001081
Cirrhosis
Scar tissue replaces healthy tissue in the liver
0001394
Congestive heart failure
Cardiac failure
Cardiac failures
Heart failure
[ more ] 		0001635
Conjunctival telangiectasia
Small dilated blood vessels near membrane covering front of eye and eyelids
0000524
Esophageal varix
Enlarged vein in esophagus
0002040
Gastrointestinal hemorrhage
Gastrointestinal bleeding
0002239
Hematuria
Blood in urine
0000790
Hemoptysis
Coughing up blood
0002105
Hepatic failure
Liver failure
0001399
Intestinal polyposis 0200008
Nephrolithiasis
Kidney stones
0000787
Peripheral arteriovenous fistula 0100784
Pulmonary arterial hypertension
Increased blood pressure in blood vessels of lungs
0002092
Pulmonary embolism
Blood clot in artery of lung
0002204
Retinal telangiectasia 0007763
Seizure 0001250
Subarachnoid hemorrhage 0002138
Transient ischemic attack
Mini stroke
0002326
Venous thrombosis
Blood clot in vein
0004936
1%-4% of people have these symptoms
Cerebral arteriovenous malformation 0002408
Pulmonary arteriovenous malformation 0006548
Spontaneous abortion 0005268
Spontaneous, recurrent epistaxis
Recurring nosebleed
Spontaneous, recurrent nosebleed
[ more ] 		0004406
Percent of people who have these symptoms is not available through HPO
Anemia
Low number of red blood cells or hemoglobin
0001903
Arteriovenous fistulas of celiac and mesenteric vessels 0002642
Autosomal dominant inheritance 0000006
Brain abscess 0030049
Clubbing
Clubbing of fingers and toes
0001217
Cyanosis
Blue discoloration of the skin
0000961
Dilatation of celiac artery 0100858
Dilatation of mesenteric artery 0011934
Dyspnea
Trouble breathing
0002094
Fingerpad telangiectases
Small dilated blood vessels in fingerpads
0006107
Gastrointestinal angiodysplasia 0000471
Gastrointestinal arteriovenous malformation 0002629
Gastrointestinal telangiectasia
Small, enlarged blood vessels near skin
0002604
Hematemesis
Vomitting blood
0002248
Hematochezia
Rectal bleeding
0002573
Hepatic arteriovenous malformation 0006574
High-output congestive heart failure 0001722
Ischemic stroke 0002140
Lip telangiectasia 0000214
Melena 0002249
Nail bed telangiectasia 0001232
Nasal mucosa telangiectasia
Spider veins of mucosa of nose
Spider veins of mucous membrane of nose
Spider veins of nasal mucous membrane
[ more ] 		0000434
Palate telangiectasia
Telangiectasia of the roof of the mouth
0002707
Polycythemia
Increased red blood cells
0001901
Right-to-left shunt 0001694
Spinal arteriovenous malformation 0002390
Tongue telangiectasia 0000227
Venous varicosities of celiac and mesenteric vessels 0002626
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Although current treatment cannot stop telangiectasias or arteriovenous malformations (AVMs) from forming, many of the symptoms and complications associated with hereditary hemorrhagic telangiectasia (HHT) can be treated or prevented.[4] Management of HHT includes checking for new or worsening AVMs and the treatment of complications such as nosebleeds, bleeding from the intestines or stomach, and anemia. Treatment of AVMs of the lung (pulmonary), brain (cerebral) and liver (hepatic) may also be recommended. [2][4]

Reducing the number and severity of nosebleeds can help prevent anemia. Treatment of nosebleeds may include using a vaporizer to increase the moisture of room air and keeping the inside of nose moist using nasal lubricants or sprays. Laser therapy may be used to remove the abnormal blood vessels (laser ablation). Other treatment may include medication or hormone therapy, but the effectiveness and safety of these treatments has not been established. If the nosebleeds continue despite other treatment, skin from a different part of the body may be grafted to replace the thin lining of the nose (septal dermoplasty) in an effort to cover and protect the fragile telangiectases.[2][4]

Bleeding in the intestine or stomach is usually only treated if oral iron supplements cannot keep iron levels high enough to avoid anemia. Treatment may include surgical removal of AVMs or laser therapy to destroy and close the AVMs. If severe bleeding with uncontrolled anemia develops, treatment of AVMs in the stomach or intestine may include medication or hormone therapy, but the effectiveness and safety of these treatments has not been established. In addition to oral iron supplements, anemia may be treated by intravenous (IV) iron therapy or, in more severe cases, red blood cell transfusions.[2][4] 


Treatment of AVMs of the lungs (pulmonary AVMs) is recommended if the person with HHT is having a hard time breathing (dyspnea), is unable to exercise without extreme fatigue (exercise intolerance), or has low blood oxygen levels (hypoxemia). Treatment of pulmonary AVMs may also be performed to prevent lung hemorrhage and the neurologic complications of brain abscesses and/or stroke. Treatment may include inserting a small inflated balloon or small metal coil in the artery that leads into the AVM in order to stop the blood flow through the AVM (embolotherapy) or surgical removal of the AVM.[2][4] People with pulmonary AVMs are advised to take extra precautions to avoid serious complications. These recommendations include taking antibiotics before dental or surgical procedures, using special filters in IV lines to prevent even tiny air bubbles from entering the blood stream, avoiding blood thinners and non-steroidal anti-inflammatory drugs (such as aspirin, ibuprofin, and naproxen), and regular monitoring by a doctor familiar with HHT.[4]

AVMs in the brain (cerebral AVMs) greater than 1.0 cm in diameter may be surgically removed. Alternative treatment includes inserting a small inflated balloon or glue-like substance to stop the blood flow through the artery involved in the AVM (embolotherapy) and/or using a narrow, focused beam of radiation to destroy the AVM (stereotactic radiosurgery).[2][4]

AVMs in the liver (hepatic AVMs) are currently treated only if a person shows signs of heart failure or significant health problems related to the liver not working properly. Treatment might include standard heart failure medications, liver transplantation, or medications like bevacizumab.[4]

In addition, guidelines for people with HHT recommend annual evaluations for anemia and neurologic conditions and re-evaluation for pulmonary AVMs every one to two years during childhood and every five years thereafter. Blood tests to check for anemia may be recommended more often depending on the frequency and severity of nose bleeds or if an intestinal or stomach AVM is bleeding. Women with HHT considering pregnancy are screened and treated for pulmonary AVMs; if pulmonary AVMs are discovered during pregnancy, they are treated during the second trimester.[2]

Last updated: 10/13/2017

Management Guidelines

  • The International HHT guidelines goal was to develop evidence-informed consensus guidelines regarding the diagnosis of HHT and the prevention of HHT-related complications and treatment of symptomatic disease.  Click on the link to read the abstract for the International Guidelines,  published in February 2011 in the American Journal of Medical Genetics.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Hereditary hemorrhagic telangiectasia. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Parent and Caregiver Resources

  • In this NCATS Video Profile, Jessica McQuillen discusses her life with hereditary hemorrhagic telangiectasia.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
    Orphanet
    Orphanet
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Hereditary hemorrhagic telangiectasia. Click on the link to view a sample search on this topic.

Selected Full-Text Journal Articles

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I have a family history of HHT. I was told I have COPD and COPD related-anemia. Is it possible that HHT caused the COPD? See answer

  • Can hereditary hemorrhagic telangiectasia (HHT) be treated? See answer


  1. Haldeman-Englert C. Osler-Weber-Rendu syndrome. MedlinePlus. April 20, 2015; http://www.nlm.nih.gov/medlineplus/ency/article/000837.htm.
  2. McDonald J & Pyeritz RE. Hereditary Hemorrhagic Telangiectasia. GeneReviews. 2017; https://www.ncbi.nlm.nih.gov/books/NBK1351/.
  3. Hereditary hemorrhagic telangiectasia. Genetics Home Reference (GHR). February 2007; https://ghr.nlm.nih.gov/condition/hereditary-hemorrhagic-telangiectasia.
  4. Diagnosis & Treatment. Cure HHT. https://curehht.org/understanding-hht/diagnosis-treatment/. Accessed 3/14/2018.