The terms quiet BPD and high-functioning BPD, which are not diagnostic labels, refer to people who may not have stereotypical symptoms of BPD, such as angry outbursts or self-harming behaviors. Instead, symptoms and emotions are often directed inward or only come out in "pockets," such as when the person is triggered by certain people or situations. These individuals may seem calm and collected on the surface, but in reality they struggle from intense loneliness, shame, and self-criticism.