Tick bites are sending more people to the ER this summer. An expert explains why.

Emergency room visits for tick bites this year are at the highest levels since 2019, according to data from the Centers for Disease Control and Prevention.

The rise is especially prevalent in the Northeast, where June figures show 229 tick bites per every 100,000 visits to ERs — up from 167 per 100,000 visits in June 2024.

Tick bites can land someone in the hospital due to a number of tick-borne illnesses. Lyme disease, for example, can cause severe symptoms in people who were bitten by ticks carrying the borrelia bacteria. Different types of infected ticks can spread other bacteria, viruses and parasites that make people sick. For example, black-legged ticks, also called deer ticks, can also spread babesiosis, anaplasmosis and Powassan virus disease.