|Stress is very important because, although it is not a disease in itself, it has many effects on your physiology which can exacerbate other problems. Stress has been related to peptic ulcers, cardiovascular disease, lowered immunity, and many more conditions. None of these diseases are caused by stress, but stress can certainly make them worse.|
It is the same situation with pain. When you are stressed certain things happen in your body which can cause or worsen pain. The limbic system in your brain, for example, provides a link from your emotional state to your muscles. When you are stressed you have increased muscle tone which can lead to problems. The areas most commonly affected are the muscles around the spine and shoulders (Janda, 1991). This is one of the mechanisms by which stress can result in pain where there was previously no injury.
Another important effect of stress is the reduction in levels of serotonin. This neurotransmitter inhibits pain perception, and lack of it lowers your pain threshold (Apkariana et al, 2005). Abnormal serotonin levels affect your sleep patterns, which can increase stress, but also disturbs your cortisol levels.
Cortisol is a hormone that is released all the time, but more so at certain times of day and when you are under stress. Increased cortisol causes pain relief, but can also have a wide variety of negative effects. If the daily cycle of cortisol release is altered, as with sleep disturbance, it can mean that the pain inhibitory effect of cortisol is not working at a time to suit you, meaning you experience more pain during the day for example.
These three actions of stress can increase pain levels, which in itself can be a stressor, perpetuating the problem.
This is only a very brief and simplistic overview of how stress relates to pain, but it demonstrates that to look after yourself you must pay attention to all aspects of your health; physical, psychological, and physiological.
Al'Absi M, Petersen K, Wittmers L. Adrenocortical and haemodynamic predictors of pain perception in men and women. Pain 2002; 96(1-2):197-204
Apkariana A, Bushnell M, Treeded R, Zubieta J. Human brain mechanisms of pain perception and regulation in health and disease. European journal of pain 2005; 9(4):463-484
Janda V. Muscle spasm- a proposed procedure for differential diagnosis. Journal of Manual Medicine 1991; 6:136.