@peach414144- Good morning. For the past 13 years, I have had many ground glass nodules in my lungs. I have what is called multifocal adenocarcinoma. There are many reasons for ground glass opacities but if they change and grow, yes they might be considered cancer, as mine have been.

This link will show you some of the causes of ggo (ground glass opacities)
https://radiopaedia.org/articles/ground-glass-opacification-3?lang=us
No, they do not hurt. These findings are early (when was this discovered) so you shouldn't feel a thing. I had a GG opacity in my lower left lung for 5 years and it has only grown 3cm in 5 years. That's like 3 dots of a pencil. Our lungs are huge so it takes a lot to cause pain in size.

Introduction. Ground-glass nodules (GGNs) on computed tomography (CT) are hazy lesions that do not obscure underlying bronchial structures or pulmonary vessels. GGNs are manifestations of both malignant and benign lesions, such as focal interstitial fibrosis, inflammation, or hemorrhage (ncbi)

Peach, when was this found?