Which symptom indicates the progression of Lyme disease if untreated?

Arthritis is a well-documented symptom that indicates the progression of Lyme disease if left untreated. Lyme disease is caused by the bacterium Borrelia burgdorferi, which is transmitted to humans through the bite of infected ticks. In its early stages, Lyme disease may present with flu-like symptoms, but if it is not treated with antibiotics, it can lead to more severe complications.

One of the significant late manifestations of untreated Lyme disease is Lyme arthritis, which typically occurs weeks to months after the initial infection. Patients often experience recurrent episodes of joint swelling, pain, and inflammation, most commonly affecting the knees. The presence of arthritis is not only characteristic of late-stage Lyme disease but also serves as a definitive indicator that the disease has progressed beyond its early stages, highlighting the importance of early diagnosis and treatment.

Pneumonia, anemia, and nausea are not commonly associated with the progression of Lyme disease. While individuals with Lyme can experience various non-specific symptoms, these three options do not reflect the significant late complications that arise from untreated infections. Hence, arthritis stands out as a hallmark sign of the disease’s advancement.