hi madam,
welcome to Health Care Magic,
I can certainly understand your concern towards your swelling all over the body, its better to rule any hypothyroid condition, as there is sudden weight gain and get your T3, T4,AND
TSH done and please get back to me with the reports
If there is no abnormality with thyroid , another possibility could be that you have to undergo renal function tests,
liver function tests, chest x-ray and ECG, as it could be related to heart problem, and it is required to treat the cause accordingly, consult your doctor with all these reports, hope this information would help you.
please post your further questions if any
thank you