Lyme Disease Cases Increase in Warmer, Humid World

In 2025, people are seeking emergency care for tick bites in the highest level since 2017, according to data from the U.S. Centers for Disease Control and Prevention (CDC). The CDC also reported that cases of Lyme disease have continued to rise through the years.

According to CNN, experts said these increases are driven by warmer temperatures due to climate change. And as ticks expand into places where people are less familiar with the risks and how to prevent disease—such as the U.S. and Canada—the risk of Lyme and other diseases becomes more significant.

Some people may also see more than one rash on different parts of their body. As the disease develops without treatment, more serious symptoms may emerge and can last for months or even years. Lyme disease-carrying deer ticks are mostly active when temperatures are above 45 degrees Fahrenheit, and they thrive in areas with at least 85% humidity, according to the U.S. Environmental Protection Agency.

The rise in temperatures and humidity also raises the threat of mosquito-borne diseases such as West Nile, dengue, and malaria.