Here are a few of them. Imagery can help stimulate the release of endorphins into your body. Visualization of what you want to have happen seems to trigger the correct physical response in your body. Under hypnosis you can visualize soothing, healing endorphins reducing the pain. As you do so your pain will lessen and may even completely disappear.
Deep relaxation can help relieve pain.
Some painful conditions, such as headaches or IBS, are aggravated by stress and therefore can be eased by relaxation alone. Even those conditions that are not directly stress-related can be helped with relaxation. Pain causes your muscles to tense up, and the tension makes the pain worse. You may have noticed that an injection hurts less when you're relaxed than when you're tense. It is possible to distract yourself from the pain.