What Causes Cough And Breathing Difficulty While Suffering From Sarcoidosis?

I have a nephew who was told that he has sarcoidosis and will need a lung transplant. He cough constantly and has a hard time breathing and even talking. He thinks he may be dying but is vague when I question him. How serious is this? could he be dying? If yes, how long does he have? He has already been on medicine that caused him to gain a lot of weight, but he got off the meds and has lost the weight. But the cough is constant and horrible. He smokes and drinks.