If you’re like most people, a string of nerve-racking incidents keeps you in fight-or-flight response—and out of homeostasis—a large part of the time. Maybe the car cutting you off is the only actual life-threatening situation you encounter all day, but the traffic on the way to work, the pressure of preparing for a big presentation, the argument you had with your spouse, the credit-card bill that came in the mail, the crashing of your computer hard drive, and the new gray hair you noticed in the mirror keep the stress hormones circulating in your body on a near-constant basis. Between remembering stressful experiences from the past and anticipating stressful situations coming up in your future, all these repetitive short-term stresses blur together into long-term stress. Welcome to the 21st-century version of living in survival mode. In fight-or-flight mode, life-sustaining energy is mobilized so that the body can either run or fight. But when there isn’t a return to homeostasis (because you keep perceiving a threat), vital energy is lost in the system. You have less energy in your internal environment for cell growth and repair, long-term building projects on a cellular level, and healing when that energy is being channeled elsewhere. The cells shut down, they no longer communicate with one another, and they become “selfish.” It’s not time for routine maintenance (let alone for making improvements); it’s time for defense. It’s every cell for itself, so the collective community of cells working together becomes fractured. The immune and endocrine systems (among others) become weakened as genes in those related cells are compromised when informational signals from outside the cells are turned off. It’s like living in a country where 98 percent of the resources go toward defense, and nothing is left for schools, libraries, road building and repair, communication systems, growing of food, and so on. Roads develop potholes that aren’t fixed. Schools suffer budget cuts, so students wind up learning less. Social welfare programs that took care of the poor and the elderly have to close down. And there’s not enough food to feed the masses. Not surprisingly, then, long-term stress has been linked to anxiety, depression, digestive problems, memory loss, insomnia, hypertension, heart disease, strokes, cancer, ulcers, rheumatoid arthritis, colds, flu, aging acceleration, allergies, body pain, chronic fatigue, infertility, impotence, asthma, hormonal issues, skin rashes, hair loss, muscle spasms, and diabetes, to name just a few conditions (all of which, by the way, are the result of epigenetic changes). No organism in nature is designed to withstand the effects of long-term stress.