Lyme disease is caused by tick bites from a bacteria some carry.
Lyme disease , also known as Lyme borreliosis , is an infectious disease caused by bacteria of the Borrelia type . The most common sign of infection is an expanding area of redness on the skin , known as erythema migrans , that begins at the site of a tick bite about a week after it has occurred . Lyme disease is transmitted to humans by the bite of infected ticks of the Ixodes genus . Usually , the tick must be attached for 36 to 48 hours before the bacteria can spread .