Alpha-1 Antitrypsin Deficiency (AATD)


Alpha-1 antitrypsin deficiency (A1AD) is a disease passed down from your parents. It can cause lung and liver disease. Alpha-1 antitrypsin is a protein the liver makes to protect the lungs and other organs from harmful effects that may be caused by other proteins in the body. Sometimes, the protective protein is improperly shaped and becomes stuck in the liver. The lungs then can become damaged when this protein is not released from the liver to protect them. This can make breathing difficult.


The most common symptom of A1AD is shortness of breath after physical activity. This can limit the patient’s ability to exercise and can cause wheezing when breathing. Other common symptoms include:

  • Unintentional weight loss
  • Vision changes
  • Fatigue
  • Repeated respiratory infections
  • Rapid heartbeat when standing
  • Barrel-shaped chest

A1AD also can cause other conditions and patients may experience symptoms associated with conditions such as:

Causes and Risk Factors

A1AD most commonly begins to show symptoms in adults between the ages of 20 and 50. It is an inherited condition, meaning that if a patient has parents or other family members with the disease, they have a higher risk of developing it as well. Smoking increases the risk of developing related conditions such as emphysema or COPD.


Diagnosis of A1AD usually begins with a patient medical history, family history, review of symptoms and a physical exam. A1AD often causes other lung conditions, such as emphysema. It frequently goes undiagnosed or may be mistaken for asthma.

The only way to accurately diagnose A1AD is with blood tests. These tests look at the genes associated with the condition, the type of alpha-1 antitrypsin protein present in the blood, and the amount of alpha-1 antitrypsin in the blood.

Other diagnostic tools, including magnetic resonance imaging (MRI), x-rays and computed tomography (CT) scans of the chest, may also be used to diagnose related conditions. These imaging tests look at the soft tissue and bones in the body. Liver functioning tests, pulmonary tests, or a liver biopsy may also be performed to diagnose any conditions that may have resulted from A1AD.


The aim of A1AD treatment is to prevent or slow the progression of lung disease.

Patients can manage their disease through lifestyle changes, such as quitting smoking, which effectively reduces symptoms.

Longterm treatment of A1AD will depend on how severe the condition is and any related conditions that develop. Patients with A1AD should have their lung and liver functions monitored. In addition, annual flu and pneumonia shots are especially important for patients with the disease, as respiratory infections can cause lung damage.

Medications such as corticosteroids for chronic obstructive pulmonary disease (COPD) and bronchodilators to promote better breathing also may be used.

The multidisciplinary team at the Alpha-1 Antitrypsin Deficiency Program can help determine the best treatment option for each patient.

© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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