Angiogenesis is the growth of blood vessels from the existing vasculature. It occurs throughout life in both health and disease, beginning in utero and continuing on through old age. Capillaries are needed in all tissues for diffusion exchange of nutrients and metabolites. Metabolic load on demand dictates proportional changes in angiogenesis and, hence, proportional changes in capillarity. The proven fact that control of angiogenesis could have therapeutic value has stimulated greatinterest during the past 40 years. Stimulation of angiogenesis can be therapeutic in ischemic heart disease, peripheral arterial disease, and wound healing.Decreasing or inhibiting angiogenesis can be therapeutic in cancer, ophthalmic conditions and rheumatoid arthritis.