What are the themes that dominate Edgar Allan Poe's works?

The three major themes of Edgar Allan Poe's short stories and poems are untimely death, insanity, and horrific gore. These themes reflect his life. Most of the women in his life died of tuberculosis, a disease where the victim coughs up blood and drowns in it. This probably caused the untimely death and gore. Poe became insane in the latter part of his life, so he got the inspiration for the theme of insanity from his own brain.

Depending on which stories and poems you are studying - mostly the umbrella themes would deal with madness of the mind or the dark side of human nature. Also, in The Cask of Amontillado he focuses on the notion of revenge (albeit, irrational). The reasoning for revenge stems from the narrator's madness.

In addition to Poe's more famous mystery, horror and detective fiction, he wrote stories of humor, satire, fantasy and even science fiction.

Poe had an almost morbid fascination with insanity, death, human nature and the dual nature of almost everything. The Gothic era is a branch of Romanticism, therefore Poe's work follows the Romantic era trend of emphasizing the role of emotions in human nature, often in a dark context.

He had a really big interest in paranoia. In some of his short stories he had the main character fearing the thought of getting caught and that made them [him/her] go insane.

The significance of pain and horror.