Lyme disease is an infection that is spread by ticks. You can get Lyme disease if you are bitten by an infected tick. But most people who have had a tick bite do not get Lyme disease. Lyme disease is common in the United States. It can also be found in Canada, Europe, and Asia.
Lyme disease is caused by bacteria. Infected ticks spread the bacteria by biting people or animals.
One sure sign of Lyme disease is a round, red rash that spreads at the site of a tick bite. This rash can get very large. Flu-like symptoms are also very common. People in the early stages of Lyme disease may feel very tired and have headaches, sore muscles and joints, and a fever.