I'm really concerned about my sister who's been in treatment for pulmonary tuberculosis for a bit now. Her recent x-ray showed 45% damage on her right lung and 15% on the left one. These numbers worry me, and I'm unsure if this is a serious issue. The doctors mentioned lung cavities. Does this mean shes in a risky situation? Also, shes able to sit and walk but gets tired quickly when walking for too long. Shes only 20 years old. Is there any possibility that her lungs can heal and return to their original state? I'm wondering if the damage can be reversed since she's still young.