Pain killers cannot provide complete relief of pain. They may reduce, but cannot eliminate pain. Most of us do not realize the importance of tissue healing and we keep on taking pain killers to reduce the symptoms and get back to work with a temporarily painless though unhealed back, making more prone to injury thereafter. The study, involving more than 6,000 people, also found patients taking anti-inflammatory painkillers were 2.5 times more likely to suffer problems such as stomach ulcers and bleeding.