I was on 10mg of Lisinopril for 6 weeks (switched from Azor). After the first 3 days, I was having trouble swallowing . . . this went away 2 days later. Then, I was having trouble breathing, sinus problems, dizziness and constant FATIGUE during the course of the 6 weeks. I am a very active, energetic, 30 year old male. I'm not overweight, and play basketball 2 or 3 days a week. I really think I have White Coat Syndrome (170/110 at dr's office - 130/75 at home), but better safe than sorry.I could not even run for more than 5 minutes straight without feeling like I might pass out. I would have to say during those 6 weeks, I was functioning about 50% of normal, at best. I tried to stick it out to see if the side effects would go away; they only seemed to get worse over time. My Doctor said it was the "summer fever" and allergies. I felt it was the medication, especially after reading these posts, so I switched doctors. My new doctor took me off of this medication. He said Lisinopril can has been known to effect your lungs and cause breathing problems. He is located in the same practice as my previous doctor. Why she didn't inform me of any side effects, I'm not sure (thanks for nothing). All of my terrible symptoms were gone within a week. I am now taking Bystolic (5 weeks), and feel normal again. My father has been on 30mg of Lisinopril for 12 years, and never had any problems. I believe everyone reacts to medications differently. I am now on my 3rd medication in 7 months, and think I have found the one that works best. I guess I'm just one of those people that has trouble adjusting to medication. Good luck to those of you that have not found the right medication yet.