 [ Symptoms ] what do i do if my blood sugar is 558 and i have congestive heart failure and never noticed sugar problems before  my friend checked my sugar and it was 550 and 10 mins later it was 558 and i have been very thristy and sleepy i have not noticed a problem with my bllod sugar before i have had this problem with my levels being no less than 427 as my blood sugar and today is the third day since i have been checking it please respond back asap [ Disease ] most likely you have diabetes and you need to see the doctor to get your blood sugar down how do know you have heart failure if you have been to a doctor that has told you this i am not sure why they did not check your blood sugar and blood pressure etc