Stress comes in multiple forms, and contrary to popular belief not all of it is bad. We normally associate stress with mental or emotional pressure in an unhealthy context such as working too much or being in an abusive relationship. But mental stress can be healthy also. It can push a person to learn new limits of mental focus and emotional patience.
Physical stress can be very healthy. All forms of exercise are a physical stress, it is pushing your body to be stronger, faster more coordinated. However, an example of unhealthy physical stress is going for your normal exercise with an injury and pushing yourself through the pain. Chemical stress we most often think of as introducing poisons into our body; smoking, alcohol consumption, eating sugar. But the good side of chemical stress is altering your diet for the better. Eating more healthy foods, changing the times that you eat within the day.
Stress is essentially an introduction of external force on a system. When it comes to stress on ourselves we should be regularly evaluating what kinds of stress we are introducing to ourselves. If it is something that we are capable of adapting to and for how long. Is this a healthy stress? Or is it impacting us in an unhealthy and unsustainable manner.