Thanks for writing to H.C.M. about your query.
I have gone through your query regarding cough and phlegm some times mixed with blood. as you said that you are occasional smoker, but due to blood in phlegm you are much worried. Here I would like to tell you some diseases where blood is found in sputum.-
(1) Acute Pharyngitis
(Acute sore throat).
(2) Pulmonary tuberculosis
(3) Tumour base (posterior part) of tongue.
(4) Tumors of larynx and pharynx.
may be pathological, drug side effect or idiopathic.
(7) Tumor of nasopharynx- in these cases usually nasal bleeding
is also noted along with blood in sputum.
Since you are having chronic cough
therefore for making diagnosis following investigations are necessary-
(1) X-Ray chest in P.A.view.
(2) Sputum for AFB, Culture and sensitivity, Malignant cells.
(3) Blood - CBC, B.T., C.T., Prothrombin time
(4) Pan endoscopy- ( Nasal endoscopy, Pharyngoscopy, Direct Laryngoscopy
Working on these lines with thorough clinical examination and co-relation with inferences of investigations one can reach to correct diagnosis and that can be manage accordingly.
I hope now your query is explained.