What causes an elevated reverse t3 (liothyronine) level but the other thyroid levels are normal thyroid??? my reverse t3 (liothyronine) was 35

Many causes: First, I am impressed your doctor tested reverse T3 as few doctors ever check it. There are many possible causes of increased reverse T3 including high cortisol (from chronic stress, emotional or physical), inflammatory conditions, injuries and infections like Lyme disease (which is surprisingly common and often undiagnosed). See http://www.stopthethyroidmadness.com/reverse-t3/ for more info.