Why were medieval towns overcrowded?

Medieval towns were often overcrowded due to a combination of factors including rural depopulation, as people migrated to urban areas in search of better economic opportunities and security. The growth of trade and industry attracted more residents, leading to densely populated living conditions. Additionally, limited space within town walls and insufficient infrastructure to accommodate the influx of people exacerbated the overcrowding problem. This often resulted in poor sanitation and increased susceptibility to disease.