...the novels and short stories of Franz Kakfa...dramatize an all-consuming anxiety created by the emotional isolation of a bureaucratic age.

  - e-notes

Sleep, quality of sleep, and insomnia are central themes in "Metamorphosis." Sleep appears to be both the cause of and solution to Gregor's transformation and alienation. The character’s irregular sleep marks the beginning of his dehumanization. Indeed, Gregor finds himself transformed into a vermin after a night of irregular sleep. Insomnia perpetuates this dehumanization, and makes a solution to Gregor's new condition impossible. "Metamorphosis" is a metaphor for social alienation, but we offer an alternative interpretative hypothesis: it may also represent a metaphor for the negative effects that poor quality sleep, short sleep duration, and insomnia may have on mental and physical health.

       - Perciaccante