What is a Subcutaneous Infusion?

Mary McMahon
Mary McMahon

A subcutaneous infusion is an infusion of fluid under the skin. Also known as hypodermoclysis or interstitial infusion, this technique can be used in the treatment and management of many health conditions, especially when care is being provided at home. Subcutaneous infusions can be used to deliver hydration, antinausea medications, and pain management medications, along with other medications, to patients in a variety of settings including hospitals, clinics, nursing homes, and private homes.

An infusion pump is used during a subcutaneous infusion.
An infusion pump is used during a subcutaneous infusion.

In a subcutaneous infusion, a needle is inserted under the skin, rather than into a vein, and connected to an infusion pump which allows fluid to slowly enter the injection site. This may be as simple as hanging a bag of fluids and allowing gravity to do the work, or a mechanized pump may be used to precisely control the dosage and to allow the patient to adjust it, if necessary. This include pumps which can be implanted or worn by patients who need long term infusions.

Subcutaneous fluid may be administered to treat dehydration.
Subcutaneous fluid may be administered to treat dehydration.

With this technique, the body absorbs the material being infused slowly. This contrasts radically with infusions into the blood stream, which act very rapidly. Sometimes a slow uptake rate is desired, as for example when the desire is to control pain over a period of hours with the assistance of a slow drip of pain management medication. Doctors can mix specific combinations of drugs for infusion to address a variety of medical issues.

Some patients cannot take medications orally or rectally and have poor venous access, making subcutaneous infusion the best method for drug delivery. This method is also inexpensive to administer and it can be performed by people without formal medical training. People may perform the infusion at home as part of home care for family members after being shown the basics in the hospital.

This method of drug or fluid delivery reduces the risk of infection at the injection site and eliminates concerns about air emboli in the blood vessels. There are a number of subcutaneous infusion sites on the body which can be rotated to keep a patient more comfortable if long term therapy is being used. Patients and caregivers should be aware that some medications can cause skin irritation when they are infused subcutaneously. It is important to monitor injection sites to adjust the dosage or the location of the injection as needed to address skin irritation and other issues, such as edema, which may contribute to patient discomfort.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

You might also Like

Readers Also Love

Discussion Comments


Is this the same kind of thing they do when you get a TB scratch test? I remember when I went to get mine before I started college, the nurse injected something up under my skin. Is this the same kind of thing?


@mathewc23 - Yes, morphine is one of the common types of subcutaneous injections. It should probably be noted, too, that subcutaneous injections aren't the same as IV infusions (which go straight into the vein, by definition).

Morphine's actually pretty versatile though. It can be given as a continuous subcutaneous infusion, as an IV, or orally.


The article mentions subcutaneous injections being used for pain medications. Is this how they administer morphine? I always assumed it went into the blood stream since it works so quickly.

Post your comments
Forgot password?