Bruises on thighs, legs calfs appear too often did blood test cbc, paletes normal dr wants to do cortisol test can low or high cortisol cause bruise?

Yes, but...: High cortisol levels, or taking corticosteroid medication causes thinning of the skin and fragile skin vessels that predispose to bruising. Thre are usually other signs of cortisol excess. Other causes are abnormal platelet function, clotting factor deficiency, kidney or liver disease, and medications. Sometimes bruising limited to the legs is not a sign of any disease or condition.