The major function of the pancreas is to produce hormones that help balance the amount of glucose(sugar) in the bloodstream.

The two major hormones that the pancreas produces are glucagon and insulin.
Glucagon is a hormone that will stimulate the liver to convert your stored sugars(glycogen) into glucose, the form of sugar that is released into your blood. This will happen if your body feels you need more glucose in your bloodstream, like if it’s been too long since you ate.
Insulin is the hormone that does the opposite of that. Insulin causes the liver to take the glucose in your blood and turn it into glycogen. Insulin is released when your blood sugar levels are too high for homeostasis to occur.
Symptoms of high blood sugar(hyperglycemia): headaches, frequent urination, increased thirst.
Symptoms of low blood sugar(hypoglycemia): shaky hands, sweating, unusual paleness.
Normal blood sugar levels are vital to homeostasis because blood pumps all the nutrients and oxygen throughout the body.