Typical syringes are measured in cubic centimeters of volume for medications, according to pediatric doctor Jeffrey W. Hull. A syringe with 1 cubic centimeter for medicine may have markings up to 100 units for patients taking insulin to control diabetes, notes Becton Dickinson and Company.
A syringe with 1 cubic centimeter and 100 markings means every marking is 0.01 cubic centimeter per unit, says Becton Dickinson and Company. Someone who must take 75 units of insulin fills up the syringe to the mark halfway between 70 and 80. Smaller syringes, such as those with 0.3 cubic centimeters, may have markings for every unit or every half unit.
Patients measure liquids in a syringe by pulling back the plunger with the tip of the needle completely submerged in medicine, according to the Eshelman School of Pharmacy at the University of North Carolina. The edge of the plunger is made of latex, and that point lines up with markings on the outside of the syringe to ensure accurate measurements. The lines on the syringe indicate the volume of medicine delivered to the patient.
Smaller syringes lead to more accurate measurements, explains the College of Veterinary Medicine at Washington State University. People should draw a little excess medication into the syringe, and then push some out to remove any air bubbles for more accurate measurements.