Invisible chronic conditions affect the work life of people in ways that are not obvious to others due to the lack of prominent symptoms. This thesis examines the negotiation of disclosure at work for people with invisible chronic conditions. In the first phase of this study, I analyzed posts on two Reddit forums, migraine and fibromyalgia. I found different factors in the workplace that can mitigate or exacerbate chronic pain in people with invisible conditions, and how people negotiate the disclosure of their invisible condition at work. In the second phase, I created five technological design concepts that were then shown to six people with one or both of these conditions in semi-structured interviews. Based on these phases, I contribute understandings of disclosure to take into account in future design efforts, such as how disclosure is not a simple, one-time conversation, nor is concealment an easy route without adequate access to manage chronic pain privately. Additionally, I identify design implications and future areas for research.