Athymhormia is a big, fancy word that doctors use to talk about something that happens to some people when they have certain diseases or injuries.
To understand what athymhormia is, we first need to understand what "affect" means. Affect is a big word that means the way someone's emotions look or come across to other people. For example, when someone is happy their affect might be smiling and laughing, while when someone is sad their affect might be crying and looking upset.
So, athymhormia means that someone's affect is different or not there at all. People with athymhormia might look like they don't have emotions, even though they do feel things inside. This can happen because there is a problem with the part of the brain that controls emotions.
It's important to note that athymhormia is not the same thing as someone just not showing their emotions on purpose. People with athymhormia really can't control the way their affect looks to others.
Doctors might use other words like "blunted affect" or "flat affect" to describe athymhormia, but they all mean the same thing -- that someone's emotions aren't showing up on the outside the way we might expect.