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Alpha-1 Antitrypsin Deficiency Symptoms, Causes and Risk Factors

Individuals with AAT deficiency may have a wide variety of symptoms. Symptoms can appear early in life or may not begin until a person is 50 or 60 years old.

What Are the Symptoms of AAT Deficiency?

Symptoms by affected organ:


  • Shortness of breath, excessive cough with phlegm/sputum production, wheezing. These symptoms can persist and lead to a decrease in exercise capacity and a persistent low energy state or tiredness. Symptoms may occur chronically or with acute infections of the respiratory tract. Occasionally a person with AAT deficiency may have chest pain that increases when breathing in. This can be due to a life-threating collapsed lung.


  • Tiredness, loss of appetite, weight loss, swelling of the feet or belly, yellowish discoloration of the skin (jaundice) or white part of the eyes, vomiting of blood, or blood in stools.


  • Warm, red, painful lumps under the skin

What Causes AAT Deficiency?

AAT deficiency is a hereditary (or inherited) condition. AAT deficiency happens when one or both parents pass an abnormal gene to their child. Based on inherited genes, AAT levels may be normal, reduced or absent. When a child inherits an abnormal gene from each parent, it increases the severity of disease.

What are the Risk Factors?

The primary AAT deficiency risk factor is inheritance of the abnormal gene from one or both parents. Not every individual with AAT deficiency develops emphysema. People with AAT deficiency who smoke cigarettes or are exposed to secondhand smoke, work or live in a dusty environment, have a family history of emphysema, have a personal history of asthma, or a history of repeated lung infections, are at an increased risk of developing lung disease early in life.

When to See Your Doctor

The symptoms mentioned above may occur with but are not specific to AAT deficiency. You should consult your doctor if you have any of the symptoms above. However, if you are a young to middle-aged person with these symptoms, or have a family history of liver or lung disease, you should see your doctor to discuss testing for AAT deficiency.

    This content was developed in partnership with the CHEST Foundation, the philanthropic arm of the American College of Chest Physicians.

    Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel. Last reviewed August 4, 2016.

    Page Last Updated: March 13, 2018

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