What Causes Dizziness,numbness And Discomfort Between Chest?

Hello,For about 2-3 months now, my husband keeps complaining he is not feeling well, but does not know how to describe what he is feeling. He points at the area between the chest and abdomen and says that something in there just doesn t feel right. He feels as if though he is really hot, but his body temperature is normal or sometimes at around 96.5 deg F. He has been getting dizzy spells, feels jittery, feels numbness at the tips of his fingers...