[originaltext] Measuring Pain Level Is D

Measuring Pain Level Is Difficult
    Scientists have long known that pain’s intensity is difficult to measure because people experience pain differently. The pain one person rates as seven, for example, / might be four to someone who is more tolerant of pain. / These differences make it difficult to show / how well new medicines to ease pain really work. / The question is especially important / because of the increasing misuse of painkilling drugs in some countries.