Conversation: The conversation between human and AI assistant.
[|Human|] I have had a cough for a week. I went to the doctor yesterday and my lungs sounded clear. I got a prescription for a sinus infection and possibly bronchitis. I have been coughing all night and the phlegm is clear but has a sand like grainy substance? Is that normal and what is that?
[|AI|]  Hello dear, thanks for your question on Chat Doctor. I can understand your situation and problem. Grainy substance in sputum is seen mostly in lung infection. Sinus infection and bronchitis can cause lung infection. You are also not improved with the symptoms. So in your case, we should first rule of lung infection (pneumonia). So get done1. Clinical examination of respiratory system. 2. Chest x-ray. If chest x-ray is normal then no need to worry much for lung infection. Don't worry, you will be alright.