If a singer is diagnosed with emphysema, will her singing be affected?

I think it would depend how severe the disease is. If the singer does not exert themselves in any other way, so if they just simply sit or stand while singing and the disease is not very bad, probably the singer can still sing, but maybe not hold a long note. When emphysema is very bad the person can barely talk, let alone sing.

People with emphysema have trouble breathing and usually need to have an oxygen tank that they cart around. I can’t imagine that she will be able to sing for much longer.

She’s going to have problems breathing, so yes.

How this hasn’t happened to Joni Mitchell with her 2-pack-a-day habit of 40 years is a miracle.

Straight from Medline Plus (emphasis added by me):

“Emphysema is a type of chronic obstructive pulmonary disease (COPD) involving damage to the air sacs (alveoli) in the lungs. As a result, your body does not get the oxygen it needs. Emphysema makes it hard to catch your breath. You may also have a chronic cough and have trouble breathing during exercise.”

If it makes it hard to catch your breath, sad to say I don’t think she’s gonna have much of a singing career any longer (not that she was back in form for a long time in any case).

For singers to be able to fill the room with their voice, they need their lungs as a “powerhouse.” In this case, emphysema severely reduces the volume of air you can take in. Singers need all the air they can get to be able to sing well, so therefore, her singing will be greatly effected.

Breathing is pretty important to singing. I am sure it would effect her song choices. She would probably have a hard time with songs that require her to hold a note for a long time.
There are better medications now, but Emphysema is a miserable way to die. I watched my dad suffer from the time I was born until he died when I was 10. There was a lot of pain and a lot of panic. Towards the last few years he wasn’t getting enough oxygen to his brain and he became pretty volatile. I wouldn’t wish that slow death on anyone.

A diagnosis will not change her ability to sing or the quality of her vocals. The disease may eventually do so.

She will have to change her approach to music. No more huge bursts of song.
She will probably tone down the sound, and find tender ways of singing, and she may excell at it.

With Emphysema her best days are definitely behind her now, unfortunately.