COPD Severity on Breathing Tests: To Find Out Your Grade, Ask Your Health Care Provider

COPD Severity on Lung Function Tests

Dear Dr. Mahler:

I want to learn more about COPD severity. On the breathing tests, there are numbers to tell how well you are breathing. I’m still confused with moderate, severe, to very severe and what it means. Thanks.

Joseph of Kansas City, MO

Dear Joseph:

Your question about COPD severity is a common concern among many patients that I see in my practice at Valley Regional Hospital.

First, the grading of severity is based on how much air that you exhale in one second. This is abbreviated FEV1.  Here is a graph that shows what FEV1 represents.  

FEV1 is used to grade COPD severity

Diagram of spirometry to diagnose COPD. FEV1 is the amount of air exhaled in one second.

Your best value is then compared with what it is expected to be for someone your age, sex (female or male), and your height. This is called FEV1 percent predicted.

To add to the complexity of the grading of severity of COPD, testing should  be performed before and after inhalation of a bronchodilator. Albuterol is almost always used for testing.  This is called post-bronchodilator FEV1 percent predicted. Your health care provider may or may not order testing with albuterol.

Guidelines and strategies for COPD describe the following four grades for COPD based on breathing tests:

                                        Post-bronchodilator FEV1 percent predicted


MILD                                                 80% or higher

MODERATE                                         50 to 79%

SEVERE                                                 30 to 49%

VERY SEVERE                                   less than 30%

It is important to remember that your current inhaled bronchodilators can affect the results of testing. For example, if you took your inhalers at 8 am and had testing at 10 am, this likely represent the peak effect of many long-acting bronchodilators. However, if the testing is done at 3 pm, the results will not be as good.

As you can see, higher numbers for lung function are better. However, it is important to recognize that the test results are just numbers and don’t reflect how you feel or how you are breathing.

These grades are most useful in describing the types of patients with COPD in research studies. It allows comparison of different medications in similar types of individuals based on breathing test results.

Joseph – I hope that this information is helpful. Finally, you can move up or down in these grades based on more effective treatments (may go up) or following a flare-up or exacerbation (may go down).


Donald A. Mahler, M.D.

Why is my COPD getting worse even though I quit smoking?

COPD Getting Worse – What are the Possibilities?

Dear Dr. Mahler:

Why does my COPD seem to be getting worse?  After my doctor pushed hard, I quit smoking 4 years ago. I have been doing pulmonary rehabilitation at the local hospital. However, my breathing seems to be getting worse and I have 1 – 2 chest colds each year, usually sometime between fall and spring. I take Advair and Spiriva regularly, and use ProAir 2 – 3 times a day when I am active. What do you think?

Hank from Appleton, WI

Dear Hank:

That is great that you quit smoking 4 years ago. As you know, it is important not to smoke or to inhale irritants in the air.

Respiratory system - quitting smoking can prevent COPD getting worse

Diagram of respiratory system

Have you had breathing tests that demonstrate that your numbers are going down? If not, it is important to ask your health care provider to order pulmonary function tests to find out if the results have changed.

Here is one possibility for your “COPD getting worse.” It is generally believed that inhaling toxic gases and particles from cigarette smoke causes inflammation in the breathing tubes that seems to persist even if someone quits smoking. However, damage to the lining of the breathing tubes (airways) may allow bacteria to get into the walls of these tubes. The presence of bacteria causes the body to call in white  blood cells (inflammation) in an attempt to kill the bacteria. This may also explain why you have chest infections each year.

A recent study published in Nature Communications (doi:10,1038/ncomms11240) in mice supports this concept. As author Dr. Bradley Richmond stated, “This may explain why inflammation persists in COPD even after patients stop smoking.” Of interest, the researchers were able to stop the damage in the mice by using roflumilast, an anti-inflammatory medication approved to reduce the risk of an flare-up (exacerbation) of COPD.

Other possible reasons for your “COPD getting worse” are anemia, anxiety, and a heart condition. Low fitness (called deconditioning) is unlikely as you are participating in pulmonary rehabilitation. Make sure to continue your exercise program.

Once again, I encourage you to talk to your health care provider about your concerns.


Donald A. Mahler, M.D.

My Sister died from Complications of Alpha-1

Good Afternoon Dr. Mahler:

I hope you can help me with some information about Alpha-1. My sister recently died from complications of Alpha-1, this was diagnosed through an autopsy. We have no idea how long she was suffering with the disease, but was admitted to the hospital and passed 5 days later from cirrhosis, spontaneous peritonitis, and sepsis. Such a shock. I had my blood test and found that I am a carrier and unlikely? to have problems. I do have asthma and nodules in my lung so I am very concerned.

Would you suggest I have further tests to assure my lung issues

Would you suggest I have further tests to assure my lung issues are not related to Alpha 1? Thank you in advance for your assistance.

Judy from Kalamazoo, MI

Dear Judy,

I am sorry to hear about your sister.

It is important to remember that alpha-1 antitrypsin deficiency (abbreviated Alpha-1) is a liver disease that can affect the lungs, especially if someone smokes.  The Alpha-1 protein is made in the liver and is called a protease inhibitor – this means that it protects the lung from damage. The condition is most common among Europeans and North Americans of European descent.

Cirrhosis affects about 30-40% of those with Alpha-1 over the age of 50 years.  Unless your mother had another reason to have cirrhosis (like hepatitis or excess alcohol intake), her cirrhosis was likely due to Alpha-1 disease. Your health care provider should be able to tell you this from the autopsy results.

You stated that you are a carrier.  You should ask you health care provider for the exact results.  This includes the alleles (two letters) and the level of Alpha-1 in the blood.  Being a carrier means that you probably have a Z or S allele (inherited from one parent); the other allele is probably M, which is normal.  You should share this information with any siblings and children, who can then tell their health care provider.

You are correct that it is very unlikely that you will have any liver or lung problem as a carrier for Alpha-1.  Certainly, it is quite important that you do not smoke cigarettes or inhale irritants in the air.

The figure shows possible conditions associated with Alpha-1 deficiency.

Conditions associated with Alpha-1


In response to your question about additional tests:

Has your health care provider told you what is the cause of the lung nodules? There are many causes for lung nodules, and the key issue is to determine that they are benign (not cancer).  Usually, follow-up CT scans of the chest are done to make sure that the nodules are stable in size over a 2 year period.  If so, then it is assumed that the nodules are benign.

Asthma is diagnosed by a medical history AND breathing tests. If you have not had pulmonary function tests (breathing tests), you should request these.  The information can help in making the correct diagnosis and in determining how your lungs are working.  As the above figure indicates, sometimes Alpha-1 can be misdiagnosed as asthma.

Finally, the Alpha-1 Foundation is a great resource for more information.

Best wishes,

Donald A. Mahler, M.D.




Chronic Bronchitis OR Emphysema?

Hello, Dr. Mahler:

I have mild/moderate COPD.  I know both Emphysema and Chronic Bronchitis are covered under this term and the treatment is virtually identical,  but I do want to know which primarily I have.  My nurses and doctor refuse to tell me,  do you think this is because they don’t know?  I have only ever had a chest x-ray.   Do I have the right to insist please?

I am smoking and my sats are often very low 90’s and even go as low as 90.   Also I have a severe symptom which is not being able to keep up with my peers on the flat.   Are these both down to smoking as they claim,  or could there be some other cause please?

Thank you very much.

Adele from Manchester, United Kingdom

Dear Adele,

Thanks for your query. The diagnosis of COPD requires breathing tests, whereas a chest x-ray may only suggest this medical problem.

With chronic bronchitis, the person coughs up mucus from the chest most days (at least for 3 months) over at least 2 years.  If you do this, then you do have chronic bronchitis. With emphysema, the main symptom is shortness of breath with activities. A breathing test called the diffusing capacity is lower than normal in those with emphysema.  Some individuals may have components of both chronic bronchitis and emphysema.

It is possible that your doctor may not know the answer to your question if he/she has not ordered pulmonary function tests (PFTs) – commonly called breathing tests.  I suggest that you ask your doctor about ordering these tests.

Views of the inside of a normal breathing tube on left and of chronic bronchitis on the right. Note the white-yellow mucus lining the inside of the airway in chronic bronchitis.

Views of the inside of a normal breathing tube on left and of chronic bronchitis on the right. Note the white-yellow mucus lining the inside of the airway in chronic bronchitis.

Microscopic view of the air sacs (alveoli) in the top right showing emphysema (destruction and enlargement).

Microscopic view of the air sacs (alveoli) in the top right showing emphysema (destruction and enlargement).

It is likely that your breathing difficulty is due to COPD, although heart disease may also cause someone to be short of breath. PFTs are “key” to make sure of the correct diagnosis. If you do have COPD, it is  likely that “not being able to keep up with peers” is due to the narrowing of  your breathing tubes. The narrowing makes it hard to get all of the air out of your lungs when you exhale, and the “trapped air” affects the  ability of your breathing muscles (the diaphragm) to work properly.

On left: Normal size of lungs. On right: lungs are larger due to inability to exhale completely. This is called HYPERINFLATION.

On left: Normal size of lungs.
On right: lungs are larger due to inability to exhale completely. This is called HYPERINFLATION.

I encourage you to quit smoking and to ask your doctor whether inhaled bronchodilator medicine(s) may help you breathe easier  assuming PFTs do show narrowing or obstruction. This information and much more are available in my book COPD: Answers to Your Questions (published February 2015) which is presented on my website.

Best wishes,

Donald A. Mahler, M.D.