Immunology

Hereditary Angioedema (HAE) Resource Guide

At a Glance

Hereditary Angioedema (HAE) is a rare genetic condition that causes unpredictable, severe swelling driven by bradykinin. Because it is not a typical allergy, standard allergy medications do not work. However, modern targeted therapies can successfully manage HAE and prevent future attacks.

Welcome to your comprehensive guide to Hereditary Angioedema (HAE). Receiving this diagnosis often marks the end of a long, confusing search for answers, but it is also the beginning of a new chapter where you can finally take control of your health.

HAE is a rare genetic condition characterized by recurrent, unpredictable episodes of severe swelling ^[1]. Unlike typical allergies, this swelling is driven by a peptide called bradykinin, meaning standard allergy medications will not work ^[2]. While HAE is a chronic condition, a revolution in targeted medical therapies over the past decade has made it highly manageable ^[3].

This guide is designed to empower you with evidence-based information so you can navigate your care, build an expert medical team, and effectively advocate for yourself in emergency situations.

Navigating This Guide

Please use the following links to explore the different facets of living with and managing HAE:

Welcome to Your HAE Journey: Relief, Reality, and Results

Learn about Hereditary Angioedema (HAE), a genetic condition causing unpredictable swelling. Understand why it is not an allergy and explore modern treatments.

The Great Mimicker: Recognizing Symptoms and Preventing Misdiagnosis

Learn the warning signs of Hereditary Angioedema (HAE). Understand how to identify non-itchy swelling, abdominal attacks, laryngeal emergencies, and triggers.

Broken Brakes: The Biological Mechanisms of HAE Types

Learn the biology behind Hereditary Angioedema (HAE). Understand how bradykinin, C1-INH, and genetics trigger swelling in Type 1, Type 2, and HAE-nC1-INH.

Cracking the Code: Understanding Your HAE Lab Reports

Learn how to read your Hereditary Angioedema (HAE) lab report. Understand what C4, C1-INH antigen, C1-INH functional, and genetic testing mean for diagnosis.

Taking Control: Modern Strategies for Managing HAE Attacks

Learn about modern treatment strategies for Hereditary Angioedema (HAE). Understand acute on-demand options, short-term prophylaxis, and long-term prevention.

Building Your Care Team and Navigating the ER

Learn how to build a Hereditary Angioedema (HAE) care team and safely navigate the ER. Discover why you must bring your own rescue meds and action plan.

From Surviving to Thriving: Long-Term Well-Being with HAE

Learn how to thrive with Hereditary Angioedema (HAE). Understand the Angioedema Control Test (AECT), managing attack anxiety, and long-term treatment safety.

You are not alone in this journey. By educating yourself and partnering with the right specialists, a full, active life without the constant fear of swelling is entirely within reach ^[4].

Common questions in this guide

What causes the swelling in Hereditary Angioedema?

The swelling in HAE is driven by a peptide called bradykinin, rather than histamine. Because of this distinct biological mechanism, standard allergy medications like antihistamines will not stop an HAE attack.

Are there different types of Hereditary Angioedema?

Yes, there are several variations of the condition, including Type 1, Type 2, and HAE with normal C1 inhibitor (HAE-nC1-INH). Knowing your specific type is important because it directly influences your treatment options and care plan.

How is Hereditary Angioedema treated?

Modern HAE management involves highly targeted medical therapies. Treatment strategies typically include acute on-demand rescue medications to stop sudden attacks, as well as prophylactic therapies that aim to prevent swelling episodes from happening.

What questions should I ask my doctor about my new HAE diagnosis?

You should ask your specialist which specific type of HAE you have and if there are any clinical trials you might qualify for. It is also critical to establish exactly how you should communicate with them if you experience a sudden, severe attack.

Curated prompts to bring to your next appointment.

1.Which specific type of HAE do I have, and how does that influence my treatment options?
2.What is the most effective way for us to communicate if I experience a sudden, severe attack?
3.Are there any clinical trials or newer therapies for HAE that I might be a candidate for?
4.How often should we schedule routine follow-ups to reassess my disease control?

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References (4)

1
Emerging drugs for the treatment of hereditary angioedema due to C1-inhibitor deficiency.
Zanichelli A, Montinaro V, Triggiani M, et al.
Expert opinion on emerging drugs 2022; (27(2)):103-110 doi:10.1080/14728214.2022.2105834.
PMID: 35876094
2
Hereditary angioedema: Pathophysiology (HAE type I, HAE type II, and HAE nC1-INH).
Wedner HJ
Allergy and asthma proceedings 2020; (41(Suppl 1)):S14-S17 doi:10.2500/aap.2020.41.200081.
PMID: 33109319
3
Garadacimab for hereditary angioedema attack prevention: long-term efficacy, quality of life, and safety data from a phase 2, randomised, open-label extension study.
Craig TJ, Levy DS, Reshef A, et al.
The Lancet. Haematology 2024; (11(6)):e436-e447 doi:10.1016/S2352-3026(24)00081-4.
PMID: 38710185
4
A Treat-to-Target approach in hereditary angioedema: expert consensus from a European committee.
Cancian M, Caballero T, Boccon-Gibod I, et al.
Frontiers in immunology 2026; (17()):1773279 doi:10.3389/fimmu.2026.1773279.
PMID: 41766887

This guide is for informational purposes only and does not replace professional medical advice. Always consult your immunology specialist regarding your Hereditary Angioedema symptoms and emergency action plan.

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Guide Contents