The issue of women's representation and success in physics has been an important area of investigation in the physics education research community. Much of the research attempting to explore this area has focused on educational gender differences in the classroom, references to chilly climates, and work-life balance. Almost no research has specifically talked about issues of gender discrimination. This article begins such an area of research by focusing on the gender discrimination experienced by women in graduate physics and astronomy programs through the lens of microaggressions; which are subtle daily acts of discrimination. Findings indicate that women are often unconsciously ignored by male colleagues, suffer from conscious discriminatory comments, and find themselves ignored when seeking resolution to these issues. Their experiences can be understood and organized in the three main microaggression constructs: microinsults, microaggressions, and microinvalidations. This organization helps to develop a language to discuss these issues in physics and facilitate future research in the field.