I think a holistic approach to anxiety is vital. As others have stated, looking at physical factors such as diet, exercise, nutritional imbalance and the like are important. I agree that psychological factors, such as looking at one's anxious thoughts and reframing them, is also key. As an occupational therapist, I would add: How do you feel about, and think about, your overall life daily activities? Are you satisfied with your life? Are your activities and interactions meaningful, purposeful and fulfilling? If one is not feeling confident, inspired and connected emotionally and socially to others, that can lead to significant underlying anxiety, as well. I believe a holistic exploration of all these issues is a key to uncovering possible multiple factors. Thus, your approach to improvement might entail various modalities, working synergistically.