Before oxygen therapy is prescribed there are guidelines or criteria that must be met. These criteria involve a blood test. (These blood test criteria must also be met for Medicare and other insurers to pay for the oxygen costs.) Medical experts produced the criteria. They establish what the levels of oxygen in the blood must be for oxygen therapy to be needed.
If you have COPD, your doctor may check to see if you have AAT deficiency.
Symptoms of AAT deficiency include:
Shortness of breath
Frequent respiratory infections like colds, flu, or bronchitis
Unexplained weight loss
Since AAT deficiency runs in families, you may want to be tested if you have a relative with it.
Two Kinds of AAT Deficiency
People who develop the illness have two faulty genes, one passed from each parent. Genes are part of your DNA.
It's possible to have just one faulty gene, which makes you a carrier. You won't get AAT deficiency yourself, but you can pass it to your children.
If you inherit two faulty genes, you can develop emphysema in your 40s or 50s -- or you may never get symptoms of lung disease. You may never even know you have AAT deficiency. So although a test may show that you have both genes, it cannot say for certain what will happen to your health.
Blood Tests and Lung Checks
The best way to diagnose AAT deficiency is with a test that looks at your DNA. Your doctor will take a blood sample or swab the inside of your cheek. Lab workers will check the sample for the faulty genes that cause AAT deficiency.
Another blood test measures how much of the AAT protein is present in your body. If the level is much lower than normal, that's a sign of AAT deficiency.
Your doctor may also suggest tests to look for lung disease. These may include:
A CT scan. This type of X-ray can spot emphysema.
A lung test to measure how much air you breathe in and out in a short time.
A blood gas test to measure how much oxygen is in your blood.