Multiple chemical sensitivity is a reaction to various synthetic chemicals in today's environment. Patients with this condition exhibit a wide range of symptoms when exposed to low amounts of environmental chemicals that are typically considered safe for humans. The most common complaints reported by patients are headaches, dizziness, exhaustion, difficulty concentrating, earaches, sore throats, congestion, difficulty breathing, chest and back discomfort, joint stiffness, racing heart, and other symptoms of anxiety and depression. learn more about how to recover from chemical sensitivity.