Palpitations can be due to many different causes including consumption of caffeine. There is no immediate way of stopping palpitations but if they are frequent you need to see your doctor.

You have to treat the cause of palpitations. Therefore you should see your cardiologist who will do heart & blood tests including for thyroid.

There are many reasons for palpitations. You should see a cardiologist who can sort out the possible cause of your palpitations and see if there is any problem with your heart. After that, he can recommend treatment if indicated.