HAE Diagnosis & Treatment

The rarity of Hereditary angioedema (HAE), diversity of its affected population, and the overlap in symptoms with other more common diseases, such as allergic angioedema and appendicitis, make diagnosing HAE challenging and an HAE diagnosis may be delayed. Skin symptoms are often misdiagnosed as allergic angioedema. Abdominal symptoms can be misdiagnosed as appendicitis. Awareness of HAE has increased in recent years; however, patients continue to experience misdiagnoses.9 Understanding and recording the patterns of your symptoms will help your doctor make a proper diagnosis. Tell your doctor about any family history of HAE.

Your doctor may suspect you have HAE when traditional treatments for swelling don’t work, you have a positive family history, and you have a history of recurrent angioedema attacks.8 Your doctor may order blood tests to support a diagnosis of  HAE Type I or Type II. Your blood will be tested for:

  • C1-INH quantitative to count the number of C1-INH proteins in the blood
  • C1-INH function to measure how well the protein is working
  • C4—C4 protein level is typically low in confirmed cases of HAE Type I or Type II10

Types of Hereditary Angioedema8


Type I

HAE type I: most common with 85% of HAE patients affected

Type II

Type 2

HAE type II: 15% of HAE patients affected

HAE with normal C1-INH

HAE with normal C1-INH: normal levels of C1-INH and it functions normally. Extremely rare.

HAE Treatment

Guidelines recommend that all HAE attacks are considered for on-demand treatment and that any attack affecting or potentially affecting the upper airway is treated. On-demand therapy, or acute treatment, is medicine used to treat the symptoms of an HAE attack.8

Patients should be evaluated at every doctor visit (at least once a year) for the need for long-term prophylactic treatment to help reduce the likelihood of attacks in severely symptomatic HAE patients. You and your doctor should discuss whether long-term preventative treatment is right for you.

Short-term prophylactic treatment is for patients who know they will encounter a trigger and want to reduce the chance of an attack, such as a dental procedure or menstruation.

It is important to work with your doctor to develop a treatment plan that works for your individual needs.

FDA-Approved HAE Treatment Options

On-Demand Therapy

Learn About HAE

Preventative/Prophylactic Treatment

Learn About HAE Symptoms

On-Demand Treatment Solutions

Guidelines state that on-demand treatments are given at the onset of symptoms to prevent attacks from becoming more severe.1

All patients require a readily available on-demand treatment to terminate unpredictable angioedema episodes. In addition, early treatment has been shown to shorten the duration of the attack, no matter how severe it is or where it is located in the body.1


  • [1] Busse PJ, Christiansen SC, Riedl MA, Banerji A, Bernstein JA, Castaldo AJ, Craig T, Davis-Lorton M, Frank MM, Li HH, Lumry WR, Zuraw BL. US HAEA Medical Advisory Board 2020 Guidelines for the Management of Hereditary Angioedema. J Allergy Clin Immunol Pract. 2021 Jan;9(1):132-150.e3. doi: 10.1016/j.jaip.2020.08.046. Epub 2020 Sep 6. PMID: 32898710.
  • [8] Maurer M, Magerl M, Betschel S, et al. The international WAO/EAACI guideline for the management of hereditary angioedema-The 2021 revision and update. Allergy. 2022;77(7):1961-1990.
  • [9] Zanichelli A, Longhurst HJ, Maurer M, et al. Misdiagnosis trends in patients with hereditary angioedema from the real-world clinical setting. Ann Allergy Asthma Immunol. 2016 Oct;117(4):394-398.
  • [10] US Hereditary Angioedema Association. Comprehensive Table of Angioedema Types.