Generally okay. The most common symptom is anxiety just from being awake during a medical procedure. You usually get some medicine to help keep you calm. You should not feel pain due to numbing medicine. You may feel pressure while the catheter is put in and starnge feelings as it goes to the blood vessel being evaluated. When the dye is injected some folks feel flushed or warm.
Depends. If it is of the lower legs you may feel some mid discomfort in the legs as the contrast is going through the blood vessels. In the pelvis you may feel a slight burning sensation. In other locatons you will likely not feel very much if anything at all. Sedation is usually given during the exam to make you overall more relaxed and comfortable. The whole process should have little discomfort.