 [ Symptoms ] i am an avid runner but since starting 25 mg of hctz my stamina and speed has dropped off greatly is this correlated  i typically run 3 miles a day but am now winded and light headed after 1 mile my times have dropped markedly i have also noticed that i get very light headed whenever i stand up quickly and that is also new since beginning this drug my blood pressure is on the high side of normal [ Disease ] hctz is a diuetic that can lower your blood pressure it should not decrease your stamina but it could be related to your light headedness with standing quickly orthostatic hypotension i would suggest that you see your medical provider    the only that prescribed the hctz    for a consultation