What is a Hypodermic Injection?

   Hypodermic injection is a method for administering drugs under the skin. The equipment for the injection includes a syringe and a hollow needle. A syringe is a tube with a plunger attached. The needle has a sharp point, and it slips easily into the skin. The doctor attaches the needle to the syringe barrel, puts the liquid medicine in the syringe, and inserts the needle into the patient's skin. Then, the doctor presses on the plunger to force the medicine through the needle. Charles Pravaz, a French physician, invented the hypodermic syringe in 1853.
   Hypodermic injections are often named for the tissue into which the injection is made. Intradermal injections are made between the layers of skin. For these, the doctor inserts a needle just under the top layer of skin.
   Injections made beneath the layers of skin are called subcutaneous injections. Intramuscular injections are given into deep muscle tissue. A hypodermic needle can be inserted into a vein to give medicine intravenously.