The complete clinical spectrum of Lyme borreliosis has been recognized for nearly 50 years, yet its diagnosis remains challenging due to the heterogeneity of symptoms. While many symptoms are likely nonspecific, a recurring cluster, including severe fatigue, brain fog, cognitive decline, memory impairment, joint and muscle pain, limb numbness, headaches, and low-grade fever, is often labeled in the scientific literature as post-treatment Lyme disease syndrome (PTLDS), and in the popular media as "chronic Lyme disease." Based on clinical experience and retrospective case analysis, this study hypothesizes that in many such cases, these persistent symptoms are not sequelae of Lyme borreliosis but manifestations of an undiagnosed focal infection, most commonly chronic tonsillitis or periodontal disease. The hypothesis is supported by the observation that the symptom profile of PTLDS is remarkably similar to that seen in focal infections, and by documented patient outcomes following treatment of these localized infections. This study compiles and analyzes clinical data to support the reinterpretation of PTLDS and "chronic Lyme disease" as misattributed focal infections in a subset of patients.