Insulin Blood Test

What Is an Insulin Blood Test and Why Is It Done?

An insulin test measures the amount of insulin in the blood. Doctors might order the test to:

• find the cause of low blood sugar and other conditions linked to insulin problems (like pancreas problems)
• diagnose and monitor insulin resistance (when the body doesn't respond to insulin as it should)

What Is Insulin?

Insulin is a hormone made by a gland called the pancreas. Insulin lets cells take in glucose (a sugar that comes from food), which is the body's main source of energy.

Glucose levels in the blood rise after meals. This triggers the pancreas to make insulin and release it into the blood. Without insulin, glucose can't get into the cells and it stays in the bloodstream.

• With too little insulin, blood sugar is too high (hyperglycemia) and cells can't get the energy they need. 
• With too much insulin, blood sugar is too low (hypoglycemia), causing symptoms like sweating, trembling, and lightheadedness.

Sometimes, the body makes lots of insulin, but the insulin isn’t able to work well because of insulin resistance. Depending on how well the body keeps up, the blood sugar level may be normal or high.

Top Things to Know

• The insulin test checks the level of a hormone called insulin in the blood.
• Doctors may order it to check for things like pancreas problems.
• Kids might need to stop taking certain medicines or not eat or drink before the blood test.
• Your doctor can explain what it means if insulin levels are too low or too high.

How Can I Help My Child Prepare for a Blood Test?

To help kids get ready for a blood test, find out if they need to fast (not eat or drink) or should stop taking medicines before the test. Explain what to expect during the test. If your child is nervous about it, work together on ways to stay calm. Deep breathing or even imagining being in a place that makes your child feel safe and relaxed can help.

What Do Insulin Test Results Mean?

Your doctor will explain what the results of the insulin test mean for your child. “Normal” blood levels of insulin vary based on things like age and gender.

Insulin and blood sugar are usually linked. So, when looking at the insulin level, doctors also look at the blood sugar level.

Low Insulin Level

A low level of insulin with high blood sugar could be due to type 1 diabetes or long-term pancreatitis (irritation and swelling of the pancreas).

High Insulin Level

A high level of insulin with blood sugar that’s normal or just a little high could mean the start of insulin resistance. Someone who has insulin resistance may go on to develop type 2 diabetes. Insulin resistance can also happen in people with polycystic ovarian syndrome (when the ovaries make too much of certain hormones).

Insulin that’s high or normal with low blood sugar could be due to a pancreas problem or using extra insulin to treat diabetes.

What Else Should I Know?

When kids have an insulin blood test, they’ll likely have a C-peptide blood test too. The pancreas typically releases equal amounts of insulin and a substance called C-peptide. So, measuring C-peptide helps show how much insulin the body is making.

If you have questions about the insulin test or what the results mean, talk to your doctor.