hello,
i am mother of 11month old baby boy &continuing brast feeding my son,after 6month of my delivery i diognaised by hypothyrodisum where weight is increases,my question is will it affact my baby as i am breastfed him,secondly wil it pass to my son,thirdly what are the chances of thryroid in future in my baby?

The medication will not influence your baby at all, keep on breastfeeding. You will need to take medication though, if you leave it untreated there is a good change you will end up in the hospital (do you have the numbers of your bloodtest, what was your THS number? The higher that is, the more you will have trouble losing weight and the more tired and sloughy you will be)
The future of your thyroidism is depending on what your diagnosis is. If it is pregnancy induced than it might - over time - disappear, but if it is Hashimoto's you will have it the rest of your life. Not a big deal, make sure to take your medication and have regular check-ups.
The changes of your son having this or getting this are really small, it is not contagious!
I developed hypothyroidism during my second pregnancy (Hashimoto's) and none of my kids (4 of them) have it.

Karen