Lyme disease is an illness caused by the bite of an infected tick, specifically the black-legged tick. These ticks are often found in grassy or wooded areas, and they can transmit the bacteria Borrelia burgdorferi to humans. Early symptoms may include fever, headache, fatigue, and a characteristic skin rash that looks like a "bull's-eye." If left untreated, Lyme disease can lead to more serious health issues, such as joint pain and neurological problems. It's important to take precautions when spending time outdoors, like wearing protective clothing and using insect repellent, to reduce the risk of tick bites and potential infection.