I am 26 years old and have been taking 20mg of lisinopril for ove...

GO see your doctor right away. I had those symptoms and went into kidney failure and decreased heart function.

I'm also 26 and was on 10mg for 6 years until june and was fine with a couple of tolerable side effects (mild hair loss, and intermittent dry cough). For some reason Consultant upped my dose to 20mg and made me very tired, dizzy, light headed, and going from a squatting to standing position quickly gave me several seconds of blurred vision. Doc reduced my dose to 15mg, and am much better. Want to get it reduced again, as i'm still more light headed than when on 10mg, but mch less so than when on 20. Got to find a balance to keep bp down for long term gain, whilst putting up with tolerable side effects I suppose.