Chapter 169

• —Stress means that the whole body, including the brain, is mobilized to face a threat. The heart beats faster and the metabolism is modified so that the muscles have easy access to energy, in order to flee or fight. The senses become more acute and the brain is fully focused on avoiding the threatening situation.
• "The stress reaction has been necessary for the survival of the human being since the stone age. Without it, our ancestors would not have been able to overcome the dangers of nature. Today, the body still believes that it must flee or fight when it arises stress. The difference is that, in the case of the stone age, stress was brief. The fight with flight lasted a few hours or days and then followed a period of rest. In today's society, stress is more constant and, therefore, more damaging.
• How do you know when someone is stressed? Esteban asks concerned.