My wife, 40, was diagnosed with POTS 1 1/2 years ago and takes 20mg of propranolol (beta blocker) daily for it. Otherwise, she's very healthy.
Starting a few years ago, she would notice every few weeks her left arm felt like her circulation was being cut off. It felt numb, tingling, and ached, but not enough to affect normal function. A year ago, the same thing started in the back of her left leg at the same time. She noticed that when this is happening, her left toes are cold but her right toes are not.
In the past few months, the frequency has increased a bit, and in the past few weeks it's increases so it happens approximately every other day.
What could be causing this? What kind of tests and types of doctors might help with this?