I do excercise regulary with not much problem. But yet when I walk fast, or go up the stairs and immediately walk after taking the stairs I feel lightheaded and tightness in Chest. If I take little rest for 3 - 5 minutes I am comforatble again. I am good when I lift weights. Appears that running, brisk walking and going up the stairs is making me lightheaded, tightness in chest and dizzyness. My blood tests were normal. Blood pressure is normal, Heart is good. CT scan of head is good. My Doctor could not find a reason for that. I am approaching 57 years. Not on any medication. Feel tired too, perhaps with the age.
Can anybody in the medical community help me find reason with the above symptoms,please.
Thank you.