We may not be able to control stress but we can at least understand it. Do we need stress or is stress all bad? Maybe if we were never stressed, we wouldn’t graduate from grade X to grade XI. In a very stressful situation, like a major accident or trauma, your body is taken over by stress hormones. The adrenalines create a feeling of above normal alertness, tunnel vision and time passage feels different where eight seconds feel like a life time. We also shut down pain perception. Pain is a subjective state, and if it’s the right setting we blunt it. It’s not just men in battle who don’t realise they have lost a limb, but most people experience it when for in-stance you sprain your ankle while playing with friends and hardly notice it at that time. In the face of a major physical stressor we experience incredible clarity, blocking off pain and there is also the “in the moment-ness”.
So where does this physiology come from? It seems all mammals have these attributes for evolutionary success. A deer for instance trying to escape its predator runs for its life. First it needs energy, not stored in fat cells which will take a long time to be fired up, but instant energy where adrenaline and other hormones help get the energy out of the fat cells and delivered straight to the relevant muscles. In addition, the energy needs to be delivered as fast as possible so the heart rate increases, increasing the blood pressure. Finally everything else that is not essential shuts down, for instance growth, digestion, and reproduction get turned off. We have all experienced the digestive system shutting down. When we are nervous, the first thing that happens is our mouth goes dry, since the fluids that help you digest aren’t there anymore. So if all these things are happening it’s a good thing. They help the deer escape the tiger.
What about the stresses of modern life? These rarely involve escaping a predator in this way. When we get stressed on a daily basis, we are not being physically menaced but we are turning on the stress response in anticipation of a stressor. Just by thinking of a stressful fact like maybe death, we can induce the same response in our bedrooms as we would if we were being chased by a tiger. But that’s not what the system evolved for.
So if you are a nervous human being, all of these stress responses can, for complex reasons, cause diseases such as adult onset of diabetes, chronic increase in blood pressure leading to stress-induced hypertension which causes damage to your blood vessels. Stress in the past was connected to being a good thing however, for human beings the same physiological responses that can save a deer from a tiger can actually make us sick. So as a species we need to reduce our daily mundane stressors if not for anything else, for our own survival.
The writer is a Ph.D. in Molecular Genetics and Geno-mics and is working on skin cancer at Novartis