My BP dropped to 95/67 and heart rate went up to 112bpm. I felt light headed & dizzy and heavy in the chest bit hard to breath. Very uncomfortable feeling. Goes back to normal in about 20-60 mins. Heart rate sometimes much higher & has gone as high as 170-180bpm. Felt faint. That was scary. What is causing this? All blood work & Drs tests turn out fine, including ECG& heart ultrasound. Holter monitor showed heart does skip beats sometimes but never caught an episode. Im otherwise healthy female 35 yrs old. Not overweight. Dont drink excessive, use any kind of drugs or smoke. Please help!
Hello! Welcome and thank you for asking on Chat Doctor! I read your question carefully and understand your concern. Your symptoms seem to be related to orthostatic hypotension or a postural tachycardia syn Chat Doctor.  Your performed tests can exclude any cardiac related disorders. Are your symptoms triggered by standing up from laying down or sitting position? A decrease in your blood pressure more than 20 mm Hg, when standing up, compared to sitting position would indicate orthostatic hypotension. But a head up tilt test is necessary to rule in / out the above-mentioned disorders. Further, blood lab tests (thyroid hormone levels, cortisol plasma levels, PCR, sedimentation rate, immunological tests, etc) are needed to establish the cause. Hope to have been helpful! Best regards,