Our HHT and PAVM services care for and treat patients with hereditary haemorrhagic telangiectasia (HHT, also known as Osler Weber Rendu syndrome) and/or pulmonary arteriovenous malformations (PAVMs).

Hammersmith Hospital has had a centre for specialist treatment of these conditions since 1983. We lead the British Thoracic Society’s pulmonary AVM group; from 2016 until Brexit 2021 we were the lead centre for the European Reference Network VASCERN, and we now lead the new NHS Rare Disease Collaborative Network (RDCN) for HHT.

The service receives over 200 referrals each year, provides one-stop clinics after an initial teleconsultation, and conducts on-going research. The service offers well-rounded treatment and advice about lifestyle management for people with HHT and PAVM.


1. For people with HHT and /or pulmonary AVMs: 

2. We encourage people with HHT and /or pulmonary AVMs to have the COVID vaccination when offered. 

Conditions and treatments

HHT is a genetic disorder that leads to the development of abnormal blood vessels. When present in the nose and in the gut, they may bleed. Over long periods, chronic bleeding exhausts the body’s iron stores and people with HHT may become anaemic. HHT also leads to the development of arteriovenous malformations (AVMs) such as pulmonary AVMs (PAVMs).

Pulmonary AVMs (PAVMs) are abnormal blood vessels in the lungs that can occur on their own, or in association with other conditions such as HHT.  If PAVMs are present, blood bypasses the key blood vessels in the lungs which means blood is not processed properly, leading to low oxygen levels and other complications.

While both conditions can lead to the development of other health problems, with appropriate management, people with HHT and/or PAVMs can lead normal, healthy lives.

Additional information

Clinical trials

Generations of people with HHT and/or PAVMs have contributed to our understanding of these important conditions. Usually, no specific extra study is required but from time to time there may be clinical trials running that you may want to join. These are discussed separately and are never compulsory.

Our recent studies have focused on nosebleeds and triggers, oxygen levels and exercise, anaemia, and preventing blood clots, strokes and other complications. We are developing a new 2021 website for you and your doctors to provide these results, and their integration into international consensus, through the NHS Rare Disease Collaborative Network.

Many of you participated in the 100,000 Genomes Project. We are running genomic teleconsultations from February 2021 to discuss your individual results with you – if you have not yet received a letter, please email claire.shovlin@nhs.net to set up the call.  

Further online resources