Hello, Welcome to Healthcare Magic. I have read your question fully and understand your concerns. Fluid retention with Metformin can happen but it is a rare side effect. I have seen Metformin causing fluid retention at dose of 1500-2000 mg/day. You are on 500 mg which is a small dose. Yet, may be this small dose itself is causing you to have the side effect. One way of confirming if Metformin is the causative factor for fluid retention is by stopping it and seeing if the swelling decreases. Your doctor may also prescribe you a water tablet like Furosemide 40 mg (provided there are no contraindications) to get rid of the accumulated fluid. You can then maybe restart Metformin cautiously at a later date to see if the oedema recurs. If the oedema recurs, it definitely means that Metformin is the culprit. The reason I want you to be doubly sure about Metformin is because Metformin is a good drug to lower blood glucose. It has many advantages – helps to lower blood glucose reasonably, has heart protecting features, keeps weight either neutral or causes a small decrease in weight and over all very cheap. Before completely disregarding Metformin, I would want you to give it another chance at a later date. Maybe this time around, you could start at 250 mg and gradually increase the dose and see. While you stop the metformin your doctor would prescribe you an alternative glucose lowering medication like Glimepiride/Gliclazide (which are sulphonyl ureas) or Galvus (DPP4- inhibitors) or Forxiga (SGLT-2 inhibitors). If even after stopping metformin as mentioned above, the oedema in your feet does not reduce, then there would be other potential causes for fluid retention which your doctor needs to rule out : 1) BP controlling drugs like amlodipine, diltiazem, beta blockers like carvedilol or metoprolol can cause fluid retention (you did mention that your other medicines were altered) 2) Other drugs like steroid tablets, anti-depressants cause fluid retention 3) Congestive heart failure: heart is unable to pump blood properly leading to fluid overload 4) Varicose veins etc. So, I would advise you to see your doctor to deal with your problem, as you need a proper evaluation and management. I hope this answer has helped you. I wish you a speedy recovery. Thank you Regards Dr Sunita Sayammagaru