失眠（insomnia）是指個人自覺睡眠品質不佳的主觀感受。每個人在一生中都可能會經歷失眠；壓力、生理疾病所引發之疼痛、環境影響或情緒改變，都可能導致失眠。本文依照 Walker及Avant（1995）所提出之概念分析方法，即先確立「失眠」此概念的定義及其定義性特徵，並且舉例介紹案例，分析其可能之前因後果，最後再提出實證性參考資料。期盼護理人員對「失眠」能有更正確及進一步的瞭解，進而運用於臨床護理實務中失眠的評估及照護，以提升失眠病人之生活品質。

nsomnia is an individual’s subjective perception of sleep poorly. Everyone will possibly experience insomnia in his/her life. Stresses, illnesses or diseases, environmental factors, and emotional problems all can lead to insomnia. Walker and Avant (1995) proposed a concept analysis method to identify the definition and defined characteristics of insomnia. In this article, the authors followed their methods to present examples of insomnia, analyze antecedents and consequences, and provide empirical referents. This article can improve the nurse staff’s understanding about the concept of insomnia, skillful usage in their clinical practice, and help of the patients to solve their insomnia problem.