Are blood pressure pills to blame for my puffy feet?

Whenever the weather is warm, my feet and ankles get puffy, especially by late afternoon. I've been on pills for high blood pressure for the past six months, so I'm wondering if they could be to blame, though I didn't seem to have a problem when I first started them. And should I be drinking a lot of water, or could that be making the swelling worse?

- Dr Rosemary Leonard

One of the ways the body stops overheating when the weather warms up is by widening the blood vessels, especially those near the skin's surface, which allows heat to escape. Unfortunately, this expansion can also cause fluid to leak out into the surrounding tissues, causing them to become swollen and puffy, especially in the feet and ankles, as fluid drains downwards with gravity.