Stress comes in two parts: the immediate response from the adrenal glands with adrenaline and the longer-lasting response from the adrenals with cortisol. There are specific reasons all mammals (humans and horses) have these stress systems: life is stress-filled. In the past, stress factors were much less frequent, so the body had a chance to "reset." Unfortunately, in today's world, the effect of continuous stress adds to the "set point," causing it to rise with the result that more cortisol circulates in the body. This higher level affects systems, causing increased appetite, body fat storage, and muscle degradation. Over time, obesity occurs along with equine metabolic syndrome (EMS), muscle wasting, lameness, hoof problems, immune suppression and autoimmune diseases, and other ailments commonly seen today.