Diabetes care requires continual balancing of glycemic control, complication prevention and patient-centered self-management. This handbook provides concise, practical guidance on diagnosis, glucose-lowering therapies, insulin initiation and titration, and complication screening. It includes step-by-step approaches to inpatient and outpatient glycemic management, perioperative control, and pregnancy-related diabetes care. Patient education tools, simplified titration charts and monitoring checklists support shared decision-making and safer therapy withdrawal or intensification. Sections address technology—CGM and insulin pumps—and strategies for psychosocial support and adherence. The handbook is geared to primary-care clinicians, endocrinologists and diabetes educators seeking actionable, day-to-day tools.