How big is a tick bite that can cause Lyme disease? I have a bite, but am not sure if it’s from a tick. What do tick bites look like?

Let me help. A small, red bump may appear at the site of the tick bite. This small bump is normal after a tick bite and doesn't indicate lyme disease. However, over the next few days, the redness may expand forming a rash in a bull's-eye pattern, with a red outer ring surrounding a clear area.