Painful diabetic peripheral neuropathy (PDPN) emerges as a common chronic complication in patients with diabetes. It often occurs without specific triggers and can lead to insomnia, anxiety, and depression, significantly impacting the life quality of patients. The pathogenesis of PDPN is complex and involves various factors, including hyperglycemia, oxidative stress, nutritional deficiencies, microvascular damage, and impaired insulin signaling, all of which contribute to nerve damage. Recent research has focused on investigating peripheral nervous system damage and central nervous system structural changes in PDPN patients, especially when they exhibit painful symptoms associated with small nerve fibers. Currently, there are no precise and accurate diagnostic methods or clinical treatments for PDPN. This article reviews the pathogenesis of PDPN, screening and diagnostic tools, and clinical therapeutic options.