To desensitize someone to things such as pain, anxiety, or other people's suffering, means to cause them to react less strongly to them.

Can a person be desensitize?

When a person learns to feel anxious in a situation, he can be taught to not to feel anxious by using a technique called desensitization.

What is it called when you desensitize yourself?

‌Systematic desensitization therapy is a type of behavioral therapy used to treat anxiety disorders, post-traumatic stress disorder (PTSD), phobias, and a fear of things like snakes or spiders.