There has been research in North America to validate the nursing diagnosis of anxiety. As part of this work, Young used the defining characteristics and developed a tool to measure anxiety. The present research sought to extend that study in the United Kingdom, assess the anxiety-defining characteristics tool and identify key indicators of anxiety that might be useful in clinical practice. Four anxiety measurement tools, drawn from the literature, were used. These were the state trait anxiety inventory, the graphic anxiety scale, the hospital anxiety and depression scale, and the anxiety-defining characteristics tool. A random sample of 79 hospitalized patients were interviewed and their anxiety rated using all four measures. Calculation of Spearman's correlation co-efficients revealed convergent validity between the anxiety-defining characteristics tool and the state trait anxiety inventory and the anxiety score on the hospital anxiety and depression scale. Anxiety levels were found not to be affected by the age or sex of the respondent, or the length of stay or number of previous admissions. Discriminant analysis suggested that six characteristics adequately discriminated anxious subjects: sweating, faintness, tendency to blame others, continual review of things in their mind, focus on self and a lack of self-confidence. The study concluded that there is a scope for further research into these characteristics and their use in clinical practice.