An infective disease transmitted by the bite of an infected black legged tick by borrelia bacterium. The disease develops 3 to 30 days after the bite. It has early signs and late signs. Early signs include a bull's eye rash called erythema migrans, fever, headache, joint pains and swollen lymph nodes. late signs include: severity of existing signs with involvement of systems like severe headaches, joint pains, fascial palsy, severe rash, erythema. Diagnosis is mostly clinical and on history of exposure. Treatment options include: doxycycline and amoxicillin.