Vertigo occurs when there is conflict between the signals sent to the brain by various balance- and position-sensing systems of the body. Your brain uses input from four sensory systems to maintain your sense of balance and orientation to your surroundings.
SIDE EFFECTS. Serious adverse reactions with ARIMIDEX occurring in less than 1 in 10,000 patients, are: 1) skin reactions such as lesions, ulcers, or blisters; 2) allergic reactions with swelling of the face, lips, tongue, and/or throat.
I did a quick search of arimidex and did not see weight gain as one of the side effects; however, I did see swelling of the arms and legs -- excess fluid could be a cause of weight gain. As for your cholesterol levels, it could be that you aren't eating enough of the right kinds of foods.