How was disease spread in mid evil times?

In medieval times, disease spread primarily through poor sanitation, overcrowded living conditions, and lack of medical knowledge. Contaminated water sources and spoiled food were common, while fleas and rats contributed to the spread of pathogens like the plague. Additionally, the movement of people, including trade and warfare, facilitated the rapid transmission of diseases across regions. Overall, a combination of environmental factors and social practices greatly influenced the spread of illness during this period.