International students leave their countries to pursue their educational goals in a different country and must adapt to succeed. However, they may face challenges when adapting to and learning a new culture. This study investigates the challenges common to international students in their host countries and summarizes the publishing trends. A literature search of peer-reviewed articles published in Scopus, Taylor & Francis, EBSCO Host, Web of Science, Springer, PubMed, and Wiley Online over 21 years (2002-2022) was done for data collection. After the screening, a total of 175 articles were included in this review and analyzed with content analysis. The findings show that the top four destinations for international students (USA, UK, Australia, and Canada) produced the most articles about international students' challenges. Additionally, most papers investigated more than one challenge, and sociocultural (82.9%) and academic challenges (82.3%) were the most researched, with language issues as the primary cause. The results also show no changes or improvement in the challenges of international students in 21 years, and areas such as psychological and economic challenges need more research. These challenges and other trends found in the articles are discussed and directions for future research are suggested.