Inclusion Criteria  Participant eligibility is determined according to the following criteria prior to entry into the study:  In the opinion of the investigator, the participant is capable of understanding and complying with protocol requirements. The participant or, when applicable, the participant's legally acceptable representative signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any study procedures. HAE participant (aged greater than or equal to [>=] 12 years old.) qualified to treatment with lanadelumab in the NDP and receiving treatment according to the Summary of Product Characteristics for Takhzyro. Male or female participants, aged >=12 years old.  Exclusion Criteria  Any participant who meets any of the following criteria will not qualify for entry into the study:  Currently participates or plans to participate in any interventional clinical trial. Any other reason that, in the Investigator's opinion, makes the participant unsuitable to participate in this study.  Participants should be included in the study only once. Data erroneously collected from participants for which written consent is not available, will not be included in or will be deleted from the database.