I have postural orthostatic tachycardia syndrome. Will midodrine stop as much blood falling when I stand and more return upwards?

Midodrine raises BP. Yes, midodrine is an alpha1-agonist which increases arteriolar and venous tone resulting in a rise in standing, sitting, and supine systolic and diastolic blood pressure in patients with orthostatic hypotension. You should see a cardiologist for specific doses and to assess drug responsiveness.