What is an insulin pump?

When you have diabetes and rely on insulin to control your blood sugar, insulin administration can mean multiple daily injections. Insulin pumps serve as an alternative. Instead of injections, the insulin pump delivers a continuous, preset amount of insulin, plus bolus doses when needed. Although you must still check your blood sugar levels, the pump can take the place of multiple daily insulin injections and help some people with diabetes better manage their blood glucose.

An insulin pump is a small device that closely resembles a beeper or miniature computer. Slightly smaller than a deck of playing cards, the insulin pump has several key components:

  • Reservoir: The reservoir is where the insulin is stored. It must be refilled periodically to ensure a steady stream of insulin.
  • Cannula: A small needle and straw-like tube inserted in the fatty tissue under the skin that delivers insulin. The needle is withdrawn while the tube remains. You must switch out the cannula and its site periodically to reduce infection risk.
  • Operating buttons: These buttons allow for programmed insulin delivery throughout the day and for programmed bolus dose delivery at mealtime.
  • Tubing: Thin, flexible plastic transports insulin from the pump to the cannula.

For some people, wearing an insulin pump provides more flexibility to administer insulin doses on the go without the need to carry many diabetic supplies. It also allows for a more fine-tuned dosing of basal insulin and possibly less structure around mealtime.

Insulin pumps have two dose types. The first is basal rate, which is a continuous infusion that delivers a small amount of insulin throughout the day. This insulin helps keep your blood sugar levels stable between meals and at night. The other, called a bolus dose of insulin, is given at meal times to help keep blood sugar levels in their target range after you eat a meal.

Your doctor will help you determine both basal and bolus dose amounts based on your blood glucose levels, the time of day, your typical daily routine, and your target blood sugar levels.

Wearing an insulin pump means that you must maintain the pump and the pump site. You must alternate your pump’s insertion site every two to three days to avoid infection. You must also refill the insulin reservoir as needed. To make it easier to remember, each time you change your infusion site’s location, plan to change or refill the insulin reservoir within the pump.

Several different manufacturers make insulin pumps. Read your pump’s instructions carefully to ensure you are using your insulin pump appropriately.

Insulin pumps are a safe and convenient way to deliver insulin and maintain blood sugar control, provided you use them correctly. However, they are not for everyone. Insulin pump users must test their blood sugar levels frequently and understand how to count carbohydrates so they can determine how much insulin they need at meal times. They also must manage their activity level. Although it may seem easier, using a pump takes dedication. Only those who are ready to commit to regular testing and close management of diet and exercise should consider using a pump.

Some of the risks associated with insulin pumps include:

  • added training needed to properly operate the pump
  • expense associated with purchasing and operating the pump (although some insurance plans do cover some of the costs)
  • possibility of infections at the insertion site

You must also continue to check your blood sugar levels at least four times daily to determine how much insulin you need to bolus and to see where blood sugar levels are through the day. This can alert you to the fact that the tubing or cannula has detached from your skin or has become clogged.

Also, you must disconnect your pump when you are exposed to water or excessive sweat, such as when taking a shower, swimming, or exercising in hot weather. The cannula is protected and held in place with an adhesive covering. Water can make the adhesive wear off and dislodge the cannula. You must remember to reapply the pump after water exposure. Talk to your doctor to decide when to disconnect and determine how long you can stay disconnected. Most people should not disconnect from their pump for more than two hours at a time.

Choosing an insulin pump isn’t a decision to be taken lightly. Your pump will literally be your lifeline, ensuring your blood sugar stays at target levels. The pump should be easy for you to use and wear.

Ask around

You can start by asking for recommendations. Your doctor, diabetes educator, specific diabetes blogs, and even friends of yours that wear insulin pumps are a good place to start. In addition to asking people what pumps they like, ask what pumps they’ve tried and didn’t like.

Consider costs

Your insulin pump should be a help to you, but it shouldn’t make you go broke. Contact your insurance company to determine what pumps (if any) are covered under your insurance plan. While you can certainly pay out-of-pocket for your pump, if cost is a consideration, knowing up front what options are covered can help. Another consideration to make is up-front costs versus long-term costs.

For example, some pumps are more expensive to purchase, but require less frequent replacement of cartridges, tubing, and other components. Some pumps aren’t very expensive at first, but require continual purchases of supplies that can make them less of a deal in the long run. Ideally, you’ll be wearing your insulin pump for four to five years. Take this into consideration when you look into costs.

Diabetes Forecast magazine offers a consumer guide to insulin pumps and their features. You can also explore the features of individual pumps on the manufacturers’ websites. You aren’t likely to find absolutely every feature you want in a single pump. Prioritize what features are most important to you, and try to get the pump that most closely matches these features. Examples include:


The right pump for you may depend on how much insulin you typically require on a daily basis. Some pumps don’t deliver very small doses while others may not deliver very large doses. Always check your insulin needs and ensure the pump you are thinking of purchasing will match up appropriately.


Pumps can vary significantly in how programmable they are. For example, some can’t be programmed to give bolus doses higher than 60 while others will allow you to set up two distinct sets of basal rates that can vary based on time of day, sick day needs, or exercising needs.


Ideally, a pump should have a reservoir that lasts for three days. Some people have lower insulin needs and require much less insulin per day while others have significant insulin needs and require a larger reservoir.


An insulin pump will sound an alarm when the reservoir is low or there’s a disconnection at the insertion site. For this reason, you should always ensure that you can hear your pump and that the alarm effectively alerts you to check the device.


Some pumps have tubing that connects the insertion site on your skin to the pump itself. While this means more tangling, it also allows you to read your pump more easily. The tubing-free alternative is one you wear directly on your skin. Known as a “pod” or “patch pump,” these pumps usually have a separate programmable device. If there is a problem at the insertion site the whole pod must be changed out. However, pump manufacturers are creating new pumps that are programmable and tubing-free.

Water resistance

If you anticipate being in the water quite a bit, you may wish to purchase a pump that has watertight capabilities. Always read the fine print carefully; sometimes pumps are watertight, but the remote controls for the pump are not.

You’ll also want to consider the overall appearance of the pump. Pumps come in various colors, shapes, and sizes. Since it will be a full-time accessory for you, it is important to choose a pump you don’t mind wearing.

Some insulin pumps on the market are equipped with continuous blood glucose monitoring systems. This means the insulin pump can monitor blood sugar levels throughout the day without the need to check with constant finger sticks. They do, however, still require testing to calibrate the meter.

Insulin pump manufacturers are creating ways to make these pumps “smarter” on an annual basis. For example, medical manufacturing company Medtronic has released the MiniMed 640G system. This system monitors your blood sugar levels and will cut off the insulin supply when your blood sugar dips too low. The pump will not resume your basal dosages until your blood sugar reaches a safer level. Although this system isn’t currently available in the United States, clinical trials are ongoing for its FDA approval.

Another innovation is that pumps can transmit glucose reading data to a separate location, such as a computer. While a person must be close (within at least 50 feet or less), this allows parents to monitor their child’s glucose levels while they sleep to ensure hypoglycemia doesn’t occur.

Researchers are attempting to create algorithms were insulin pumps could one day acts as an artificial pancreas. This means a person could wear an insulin pump and ideally let the pump regulate insulin release without having to make manual adjustments.