What is an insulin pump?

Insulin pumps deliver insulin in small, precise amounts and allow users to adjust dosing for meals and corrections. This ongoing delivery helps maintain more stable glucose levels between meals and overnight, while also allowing users to give additional insulin when needed. Most pumps use rapid‑acting insulin only, delivering it continuously rather than relying on long‑acting insulin injections.¹ 

Basal and bolus insulin 

Understanding insulin pump therapy starts with two key concepts: 

• Basal insulin 
  Basal insulin, often called background insulin, is delivered steadily throughout the day and replaces the need for long-acting insulin injections.¹ 
   
• Bolus insulin 
  Bolus insulin is additional insulin delivered to cover carbohydrates eaten at meals or to correct high blood glucose levels. Bolus doses are given manually using the pump or a controller, depending on the system. Many pumps include built-in bolus calculators to help estimate doses based on personalized settings.¹ 
   

How insulin pumps deliver insulin 

Insulin moves from the pump into your body through an infusion set, which includes: 

• Tubing: A thin plastic tube that connects the pump to your body  
• Cannula: A small, soft tube placed just under the skin. A needle is used to insert it, then removed, leaving the soft tube in place (often used in tubeless patch pumps) 
   

Insulin pumps and CGM sensors 

Insulin pumps can be used alone or alongside a continuous glucose monitor (CGM). A CGM measures glucose levels in real time and shows trends throughout the day and night. 

• When worn separately, the CGM provides data and alerts, while the pump continues to deliver insulin based on preset settings. 
• In connected systems (often called hybrid closed loop systems or automated insulin delivery systems), the pump and CGM communicate directly. The system automatically adjusts basal insulin delivery based on glucose readings, helping support time in range. 

Many people choose pump therapy because it can offer: 

• More precise insulin dosing in very small increments 
• Greater flexibility for meals, sleep schedules, and activity 
• Reduced need for multiple daily injections 
• Support for glucose management when paired with CGM technology¹ 
   

Who may benefit from an insulin pump 

While insulin pumps offer benefits for many people, clinical guidelines help determine who may be eligible for certain technologies. The American Diabetes Association indicates that automated insulin delivery (AID) systems, are preferred over non automated insulin pumps and MDI for those with type 1 diabetes and have largely replaced the use of standard insulin pumps (non-automated).² 

For children, adolescents, and adults with type 2 diabetes, the American Diabetes Association recommends automated insulin delivery (AID) systems as the preferred insulin delivery method (over non-automated insulin pumps and MDI).²