The other possibility is that you are coughing up blood
. This can be due to bronchitis or pneumonia, lung
cancers (especially in
smokers), tuberculosis, bronchiectasis, pulmonary embolism, or fungal and other infections.
Discuss these possibilities with your doctor. A comprehensive investigation is required keeping all the points in mind.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!