Sir from the last year I have a problem of extremely thick mucus that's struck in the back of my throat that is very difficult to clear.I have echo,ecg and chest x-ray and all are normal.Done endoscopy and colonoscopy and have normal results .But my phelgm just refuses to go..Even inhalers gives me respite only for few minutes The problem is that when this sticky phelgm gets struck I have chest heaviness and breathing trouble.But pft results show normal Yes from birth I have bronchitis but that also mild One of local doctor is suspecting cystic fibrosis but he said that's highly unlikely What is causing this? Attaching pictures of the unusual phelgm