Along with statistics, probability is one of the mathematical concepts with numerous applications in the field of medicine. For example, when studying the effectiveness of a medicine, it must be tested on a sufficiently large group of individuals, followed by analysis using probability and statistical knowledge. However, mastering the concept of probability and applying it in practice often presents various difficulties. Consequently, students are prone to making mistakes when applying probability theory in solving course exercises. This article identifies the difficulties and analyzes the common errors made by students, thereby proposing several solutions for improvement.