Thanks for your question on Health Care Magic.
I can understand your concern.
Blood in spitting can be due to either diseases of oral cavity or due to lung pathology.
Sinus disease cause blood from nose, not bleeding in spitting.
So better to first Getaway done detailed examination of oral cavity to rule out oral pathology.
If this is normal then you are mostly having
hemoptysis (blood in sputum). So get done chest
x ray and PFT (Pulmonary Function Test) to rule out
lung infection and
bronchitis. As both of these can cause hemoptysis.
So better to first diagnose yourself and then start appropriate treatment.
Sinus pathology is less likely in your case.
Hope I have solved your query.
Wish you good health. Thanks.