Consult dentist he will examine your teeth for what type of discoloration is there.some discoloration is extrinsic (that means outside the teeth, due to food, pan,tabacco,,tea,etc) can be removed by scaling and polishing or bleaching.some staining is because of intrinsic cause that'means they are in side your teeth substance, needs special treatment modalities.
Next Steps
get examined by dentist
Health Tips
brunsh after every meal