This study examines health-related issues during the COVID-19 pandemic by using tweets. The use of social media has greatly increased over the past decade. Twitter is one of the most popular sites among young adults in the U.S. Social media has increasingly become a platform where users can openly communicate about various topics, even topics as stigmatized mental illness. As a result of the COVID-19 pandemic, people experienced some drastic changes in daily life, such as physical distancing, remote learning, lockdown, travel restrictions, as well as sudden deaths, and mental health concerns. As the chance of meeting people in-person decreased due to the pandemic, people have expressed their thoughts and interacted more with others through social media. The purpose of the project is to explore the topics of depression, Post-Traumatic Stress Disorder (PTSD), and social determinants of health through use of social media data.