After turning into a bug, most of the obstacles that Gregor from The Metamorphosis encounters are physical. The newly-attained insect body is foreign and hard to control. It contributes to emotional distress as the appearance is repulsive to Gregor. He cannot go to work and has to deal with the disgust that he has for himself.
Detailed answer:
The first chapter of Kafka’s The Metamorphosis explores the physical changes of the protagonist. Gregor Samsa is turning from a human into a giant insect. The change is mystical, and the protagonist tries to go back to sleep to forget that it has happened. The physical differences between humans and insects become apparent soon. Gregor cannot lie flat on his back because its shape was no longer the same. He has more legs that stick up and move separately from the body. His belly is full of white spots, while the legs ooze a sticky substance.
Franz Kafka shows that more challenges appear when Gregor has to interact with other people in his life. Trying to talk to his mother, the protagonist realizes that his voice is different as well. He no longer talks but squeaks, with other people being unable to understand what he is saying. Moving across the room is a challenge. It is a challenge to open the door. Any other regular activity becomes unfeasible to carry out. In the first chapter, the author introduces the physical transformation of Gregor Samsa. Throughout the story, it demonstrates and emphasizes further emotional changes.