Your arteries bring blood down into your legs. Your veins carry it back up to your heart.
Amlodipine lowers your blood pressure by opening your arteries wider. That's why your numbers came down. The pill is doing its job.
But it doesn't open your veins.
So more blood comes down into your legs than your veins can carry back up. The pressure builds, and fluid gets pushed out into your lower legs, ankles and feet.
That's your swelling. And gravity makes it worse every hour you're upright: standing, walking, sitting at a desk, in the car or on a plane.
Getting it back up is your calves' job. Every time a calf muscle tightens, it squeezes the veins in your lower leg and pushes blood and fluid back up toward your heart. That's why it's called your second heart.
But your calves can only push back so much. And your pill sends down more than they can keep up with. So the extra stays in your legs.
I call it the open floodgate. Your pill opened the way in, not the way out.
It explains EVERYTHING:
Why it's worst by the end of the day. Lying down overnight takes gravity out of it, so some of the swelling drains back up. Some, not all. Then you stand up, and your legs start filling again, hour after hour, until your shoes fit at eight and won't go back on by five.
Why it started, or got worse, after your dose went up. A higher dose opens your arteries wider. More comes down, and your calves fall further behind.
Why your blood pressure looks perfect while your legs look like this. The cuff measures the way in, and the way in is working. Nothing measures the way out. There's no reading for how much your calves push back up after a day on your feet.
And it's not rare.
It's in the pill's own prescribing information: swelling showed up in 10.8% of people on 10mg, compared with 0.6% on a sugar pill. And women got it more than twice as often as men.
So why did nobody tell my mother?
Because her doctor's job was her blood pressure, and her blood pressure was perfect. Nobody's job was the way out, and there's no pill for it. So the advice circles back to the water:
Water pill → half the dose → blood pressure climbs → back to 10mg → socks and feet up → a stronger water pill.
Round and round, while nothing helps the way out.