I think i do have postural tachycardia syndrome.... what should i do? what can cause this? can losartan do this?

Doubt it: Some patients have peripheral denervation (neuropathic pots); have symptoms that are due to sustained or parosyxmal overactivity of the sympathetic nervous system (hyperadrenergic pots); and some individuals have pots dominated by features of deconditioning.Can take exrtra salt, drink 2 glasses of water before getting up, certain meds.Losartan causes postural hypotension and tachycardia, no pots.

You'll get better: The cause is unknown. Losartan doesn't cause it. Dehydration makes it worse. Drinking fluids and eating salt makes it better. In time, most people get better - may take a year for some.