II have been taking atacand 4mg for about a year for high blood pressure I have only one kidney without any concerns and this medication has controlled my kidney function blood tests. However this week I have been feeling generally unwell and feeling very lightheaded and dizzy when sitting up and standing getting out do bed. My blood pressure is lying 111/64 standing 125/78 Do you have any ideas that might explain why I,m now feeling dizzy and lightheaded. Thank you.