This study is looking for individuals who have resistant hypertension. This is a non-interventional research study and it does not involve a new drug or treatment. The goal of this study is to find out how many people with resistant hypertension, a type of high blood pressure that is hard to control, also have high levels of a hormone called cortisol. High cortisol levels, a condition called hypercortisolism, may make it more difficult to manage blood pressure. If you join the study, you will attend two to three clinic visits. During the first visit, you will go to the clinic for a short checkup. You will have vitals and your medical history reviewed. You will also have a blood draw and be given a pill called dexamethasone which will help us assess your cortisol levels. At your second visit you will fast and have a your blood collected to review your cortisol levels. If necessary, you will be invited for a third visit where you will get a CT scan. The risks associated with the study include bruising, dizziness, or, in rare cases, infection from blood draws, allergic reactions from taking the dexamethasone pill, and exposure to radiation from the CT scan. The study will be completed over the course of 2-3 visits in one months timeframe.