" But when the conditions are more subtle, things like office politics, opportunism, occasional rounds of layoffs and a general lack of trust among colleagues, we adapt. Like being at base camp on Everest, we believe that we are fine and can cope. However, the fact remains that the human animal is not built for these conditions. Even though we may think we’re comfortable, the effects of the environment still take their toll. Just because we become accustomed, just because it becomes normal, doesn’t mean it’s acceptable. On Everest, even after we’ve adapted, if we spend too long on the mountain, our internal organs start to break down. In an unhealthy culture, it’s the same. Even though we can get used to living with stress and low, regular levels of cortisol in our bodies, that doesn’t mean we should. A constant flow of cortisol isn’t just bad for organizations. It can also do serious damage to our health. Like the other selfish chemicals, cortisol can help us survive, but it isn’t supposed to be in our system all the time. It wreaks havoc with our glucose metabolism. It also increases blood pressure and inflammatory responses and impairs cognitive ability. (It’s harder to concentrate on things outside the organization if we are stressed about what’s going on inside.) Cortisol increases aggression, suppresses our sex drive and generally leaves us feeling stressed out. And here’s the killer—literally. Cortisol prepares our bodies to react suddenly—to fight or run as circumstances demand. Because this takes a lot of energy, when we feel threatened, our bodies turn off nonessential functions, such as digestion and growth. Once the stress has passed, these systems are turned on again. Unfortunately, the immune system is one of the functions that the body deems nonessential, so it shuts down during cortisol bursts. In other words, if we work in environments in which trust is low, relationships are weak or transactional and stress and anxiety are normal, we become much more vulnerable to illness. "
― Simon Sinek , Leaders Eat Last