Discomfort during Meditation

Sometimes when I make an effort to fall into soul consciousness by focusing on the nature of the breath, I feel quite a discomfort. The peace and detachment of the Atma (or so I believe) come over me in quite an intense fashion. I feel intense surges of heat, pressure in the upper abdomen and diaphragmatic area, pressure in the neck/shoulder area and a feeling of lack of breath as blood surges to my head. It throws my breathing rhythm off track and breaks my focus. The peace becomes to feel like an anxious rush for a few seconds. This happens quite occasionally - every now and then. Is this a common/normal experience or is something irregular/odd about this? Is this the sign of any shortcomings of my body which may need tending to? I ask purely to enhance my efforts at self-realization and nothing else. Please answer as you see fit.