Lyme disease is an illness usually caused by the bite of an infected deer tick and can occur year-round. The ticks are found in wooded and grassy areas near bodies of water across the United States. To prevent tick bites, wear protective clothing and use insect repellent when working outdoors. Symptoms of Lyme disease include flu-like symptoms and a circular or oblong rash. If bitten by a tick or experiencing symptoms, contact a doctor as early treatment with antibiotics can prevent serious health issues.