Diabetic patients need insulin in the following cases: 1. Diabetic patients with poor pancreatic function after examination and diagnosed with type 1 diabetes need insulin for life. 2. Diabetic patients with acute complications of diabetes, such as ketoacidosis or hyperosmolar coma, need insulin. 3. Diabetic patients with acute infections, fever or sepsis must also use insulin. 4. Insulin is also required for diabetic patients with acute cerebrovascular disease or heart disease. 5. Diabetic patients who are pregnant also need insulin to control their blood sugar.