Over 40 million Americans have diabetes — 90 to 95 percent is Type 2 — and more than 1 in 4 do not know they have it. This complete guide covers all Type 2 diabetes symptoms, the HbA1c and fasting glucose diagnostic thresholds, the DiRECT trial evidence for lifestyle reversal, the full step-up treatment pathway from Metformin to GLP-1 agonists, and the critical connection between Type 2 diabetes and erectile dysfunction in men.