Dyssemia is a big word that describes a difficulty in understanding what other people are trying to tell you through their body language, facial expressions, and tone of voice.
Picture your favorite stuffed animal, let's call it Teddy. Now imagine Teddy is trying to tell you something. Sometimes Teddy uses words, but other times Teddy nods his head, points to things, or makes a face to show how he feels. Now imagine that you have trouble understanding what Teddy means when he does those things. That's kind of what dyssemia feels like.
People with dyssemia might have a hard time knowing when someone is happy, sad, or angry, even if the person is saying the right words. They might not understand why someone is crossing their arms, tapping their foot, or turning away from them. It can make it hard to connect with other people and feel like you belong.
But just like how you might need some extra help with your homework sometimes, people with dyssemia can learn how to pick up on these nonverbal cues with practice and support from others. It just might take a little bit more effort than it does for other people.