Welcome to HCM.
Blood in cough
can occur due to various causes. Starting from infection in the throat to lots of other conditions in the airway tract.
To find out the cause a detailed examination along with blood tests, CT Scan
will be required.
Usually the doctors initially treat it as secondary to infection and if the episode repeats, then they take up detailed study.
If the episode does not recur, you do not have to worry. If it recurs then detailed investigation is must.
Wish you speedy recovery.