A Study of the Burden of Illness and Treatment Patterns in Teenagers and Adults With Hereditary Angioedema

This study is about teenagers and adults with hereditary angioedema (HAE) type I and type II. In this study, the burden of illness means the impact of HAE in terms of long-term health outcomes and the financial cost. The main aims of this study are as follows: * to learn how often, how severe and where on the body HAE attacks occur. * to describe how HAE prophylaxis and on-demand medicines are prescribed and used. (Prophylaxis medicines prevent a bleed from happening and on-demand medicines treat a bleed when it occurs.) This study is about collecting data only; participants will not receive treatment as part of this study. Existing data available in the participant's medical records will be collected. Participants will be asked to complete an electronic questionnaire either on a website or by using an app on their mobile phone; data from this questionnaire will also be collected. Participants do not need to visit their doctor in addition to their normal visits.