While Arimidex may cause high cholesterol, this is not usually a reason to stop taking it. Because there are so many effective high cholesterol treatments available, this condition can be treated while you continue to take Arimidex. While high cholesterol can be dangerous in the long run, breast cancer is usually more life-threatening and is usually a higher priority for most people. If you are concerned about Arimidex and high cholesterol, talk to your healthcare provider about your cholesterol levels (or have them tested if you have not had a recent cholesterol test). Your healthcare provider should be able to address your concerns and provide effective high cholesterol treatment, if necessary.