Subh Aarogya,
Thyroid dysfunction is metabolic disorder which can be correlated to Indigestion. In Ayurveda this can be termed as Agni dusti progressing to ras dhatu dushti....I know it's hard to understand....So please consult a near by good ayurvedic doctor. For treatment to be ayurvedic diagnosis have to be ayurvedic.
Health Tips
Have hot water prepared with powders of, Dhaniya + jeera + dry ginger..... and have it daily in morning