Thanks for asking the query,
usually ovvurs due to gingivitis
which is associated with many factors, like plague and calculus deposition, poor oral hygiene
, nutritional deficiencies, use of certain medications, endocrine changes, systemic conditions like diabetes and leukemia.
As you said you are getting blood along with sneezing you need to consult an ENT specialist
and get the checkup done.
Get your blood sugar levels checked to rule out the chances of diabetes.
Visit to a Dentist
and get a thorough checkup done.
Go for complte mouth scaling and polishing, brush teeth twice daily with a soft bristle toothbrush, use antiseptic mouthwash gargles twice daily.
Hope this helps out.