Thanks for asking the query,
causes stains on the teeth, irritation of gums, precancerous conditions & lesions and even oral cancers.
I would suggest you to quit the habit.
Visit to a Dentist
and get detailed clinical evaluation needed to confirm the diagnosis and plan appropriate treatment.
Go for symptomatic treatment of scaling and polishing of mouth.
Maintain a good oral hygiene
, use chlorhexidine
mouthwash gargles twice daily.
Hope this helps out.