that the person have a medical problem is not an imigration problem ,,, imigration have nothing to do with that even when u in hospital they not extend your visa when u not have the papers to do ,,,
overstay 1 or 2 day no problem 2 weeks have to pay a lot of money they catch u at airport and u get manny questions when its more than 1 month they can arrest u and u can be kicked out of country and blacklisted
When u really have serious medical problems u need to call your embassy to help u get home when u not able to arange your self ,, this is not a problem from imigration
Ok than first u must come to Thailand on toerist visa because non b visa can only make in here , beside of that u can get only non be when u have busines or job in here