Relapsing fever is an infectious disease caused by bacteria from the genus Borrelia. It is characterized by recurring episodes of fever, which can last several days and then subside, only to return later. The disease is typically transmitted through the bites of infected ticks or lice. Symptoms of relapsing fever include high fever, chills, headache, muscle aches, and fatigue. Diagnosis is usually made through blood tests that identify the presence of Borrelia bacteria. Treatment often involves antibiotics, which can effectively eliminate the infection and reduce symptoms.