Understanding Lyme Disease -- the Basics

Reviewed by Jennifer Robinson, MD on November 11, 2020

What Is Lyme Disease?

It's in nearly all states and 22 other countries. But most cases have been reported in these states:


• Connecticut

• Delaware

• Maine

• Maryland

• Massachusetts

• Minnesota

• New Hampshire

• New Jersey

• New York

• Pennsylvania

• Rhode Island

• Vermont

• Virginia

• Wisconsin

What Causes Lyme Disease?

Lyme disease is caused by bacteria transmitted through the bite of the tiny black-legged, or deer, tick found in the Eastern and Central U.S., and the western black-legged tick in the Pacific West. The riskiest months for Lyme disease are May through September, when young ticks are likely to be biting.

In humans, the bacteria may cause flu-like symptoms. If left untreated, it may attack many tissues -- including the heart and nervous system -- and trigger an immune response that can lead to Lyme arthritis.

WebMD Medical Reference

Sources

SOURCE: 

Centers for Disease Control and Prevention (CDC).

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