BP medications... 55 y/o female asks, What can cause my BP to be too low? Example 100/66, 93/65. Technically, those numbers are not too low with <120/90 being normal. That said, BP medications themselves are the commonest causes of low BP for age. But a host of Endocrine & metabolic disorders;low thyroid, low Adrenal function, diuretics, low salt diet and more can also do it. To prevent Syncope/Falls best see MD.
Low blood pressure. Before asking why is blood pressure low, we need to ask how you feel at time your BP is low. More worrisome if you're weak, lightheaded, dizzy, etc. In that case, see your FamilyDoc or Heart specialist immediately. BP meds are common cause of low BP. Resting/sitting/laying down BP tends to be lower than upright BP after exercise/activity. Anemia & dehydration can also drop BP. Maybe bad equipment?