Wuthering Heights blends the genres of Romanticism, Naturalism, and Realism together to achieve a balance between the three. The novel is rich in Romantic imagery and characterization: nature as good, Heathcliff as a Byronic hero, mystery and ghosts, unbridled passion, and consequences of unrequited love (revenge).
The novel also deals with the Naturalistic/Realistic themes of social class barriers, gender differences, and geography. The narration of Nelly seems very realistic, as it is modest, plain-spoken, and objective. Though, we often doubt her motivations (is she in love with Heathcliff or not?).
The novel is a great example of doubling, doppelgangers, foils, and dualities. It is two novels in one. It has two narrators, two Catherines, two Heathcliffs (hero and villain), and two settings (Wuthering Heights and Thrushcross Grange). And a lot of rabid dogs. In this way, it is a forerunner for the Gothic psychological horror tales.