Thanks for your question on Health Care Magic.
I can understand your concern.
Vibrations in the chest are commonly seen in
arrhythmia and
palpitation.
And both are common in thyroid diseases.
Since you are having hashimoto 's
thyroiditis, possibility of thyroid
hormone imbalance as a cause for your Vibrations is more.
So first get done thyroid function test.
If this is normal than get done ecg, 2d echo and Holter monitoring (24 hour continuous monitoring of ecg) to rule out arrhythmia.
If all these are normal than no need to worry for heart and thyroid problems.
Sometimes, stress and anxiety can cause similar symptoms.
So avoid stress and tension, be relax and calm.
Consult psychiatrist and discuss all these. You may need anxiolytic drugs too.
Don't worry, you will be alright, but first rule out thyroid and heart related diseases.
Hope I have solved your query.
Wish you good health. Thanks.