Last updated: Thu, Aug 15, 2024
A study back in 1969 demonstrated that subjects exhibited signs of physical arousal when merely thinking about painful experiences. Researchers in 1992 had subjects discuss or imagine painful events. They observed signs of stress and sympathetic nervous system activity—increased heart rate, increased skin conductance, and signs of tension in the frontalis muscle of the forehead. A 1999 study showed that back pain patients developed higher muscle tension from just watching others doing activities that the patients were fearful of.1
Severe pain evokes a strong sympathetic response. Epinephrine is pumped into the bloodstream, to be followed after a few minutes by cortisol. Even moderate pain evokes some of the same. This is called the “stress response.” (See The Stress Response.) Long-term exposure to cortisol, which in the short term is anti-inflammatory, can cause muscle atrophy, impair repair of tissue, and suppress the immune system.
Pain causes trouble sleeping. Lack of sleep leads to progressive malfunction of thought processes or worse.2 (See Sleep and Fatigue).
Several studies have shown that chronic pain patients selectively emphasize negative memories when asked to do autobiographical tasks.
On top of this, being tense makes the pain worse.3