The pictures that play out in our minds are often negative ones that can profoundly affect our heart rate, blood pressure, and stress levels. We picture someone who has angered us, and our blood pressure rises. We imagine an impending argument with the boss, and our body goes into a fight-or-flight response. We see ourselves flubbing a presentation, and butterflies churn in our stomach.

Just as negative images can provoke unhealthy reactions, so too can positive images inspire more healthy ones. That's the premise behind guided imagery, a practice that includes visualization.

You can practice guided imagery on your own or with the help of a therapist trained to guide you. Different images work for different people. Some people use images of nature. Others imagine their bodies healing. Others may combine the two. For instance, you might imagine that your pain is the wind, being lifted away into the sky, or water flowing downstream.

If nothing else, guided imagery promotes relaxation and calm and reduces stress, which in turn can help you sleep and lessen your pain. It can also help relax tense muscles. Talk to your health-care practitioner if you are interested in guided imagery. There are also recorded programs that can be very helpful.