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Reagents

Strips or tablets that people use to test the level of glucose (sugar) in their blood and urine or the level of acetone in their urine. These reagents are treated with chemicals that change color during the test. Each type of reagent has its own color code to show how much glucose or acetone there is at the time of the test.

Rebound

A swing to a high level of glucose (sugar) in the blood after having a low level. See also: Somogyi effect.

Receptors

Areas on the outer part of a cell that allow the cell to join or bind with insulin that is in the blood. See also: Insulin receptors.

Regular Insulin

A type of insulin that is fast acting.

Renal

A term that means having something to do with the kidneys.

Renal Threshold

When the blood is holding so much of a substance such as glucose (sugar) that the kidneys allow the excess to spill into the urine. This is also called "kidney threshold," "spilling point," and "leak point."

Retina

The center part of the back lining of the eye that senses light. It has many small blood vessels that are sometimes harmed when a person has had diabetes for a long time.

Retinopathy

A disease of the small blood vessels in the retina of the eye. See also: Diabetic retinopathy.

Risk Factor

Anything that raises the chance that a person will get a disease. With noninsulin-dependent diabetes, people have a greater risk of getting the disease if they weigh a lot more (20 percent or more) than they should.