Understanding: What are the sites for infusion?

September 28, 2025 •

4 min read

According to healthcare data, millions of people receive infusion therapy annually for various medical conditions, including autoimmune disorders and chronic infections. Understanding what are the sites for infusion is a vital part of patient education, covering different methods and the specific anatomical locations used for treatment to ensure efficacy and minimize complications.

Quick Summary

The most common sites for infusions depend on the type of therapy, including peripheral veins in the arm and hand for short-term IVs, the abdomen or thighs for subcutaneous treatments, and central veins or specialized bone marrow access for more complex needs.

Key Points

Variety of Sites: Infusion sites vary greatly depending on the type of therapy, with options including peripheral veins (arms/hands), subcutaneous tissue (abdomen, thighs), or central veins.
Intravenous (IV) Infusion: The most common IV sites are the arms and hands, using veins like the cephalic and basilic, though the inner elbow is generally avoided for long-term use.
Subcutaneous (SubQ) Infusion: SubQ injections use fatty tissue in the abdomen, thighs, and upper buttocks, offering a less invasive option often used for home therapy.
Site Rotation is Key: Regular rotation of infusion sites prevents overuse, scarring, and complications, and is crucial for maintaining effective absorption.
Complication Vigilance: Patients should monitor for signs of infiltration, infection, or phlebitis at the infusion site and contact a healthcare provider if symptoms like swelling, redness, or pain occur.
Central vs. Peripheral: Central venous access is used for long-term or difficult-to-access cases, while peripheral access is typically for short-term needs.

Introduction to Infusion Therapy

Infusion therapy involves administering medication or fluids directly into a patient's body via a needle or catheter. The specific site chosen for an infusion depends on several factors, including the type of medication, the duration of therapy, patient comfort, and the patient's age and health status. Common routes of administration include intravenous (IV), where the medication is delivered into a vein, and subcutaneous (SubQ), where it is delivered into the fatty tissue just under the skin. Less common, but crucial in specific circumstances, are intraosseous (IO) and central venous access devices (CVADs). Proper site selection and rotation are critical for preventing complications and ensuring the therapy is effective and comfortable for the patient.

Common Intravenous (IV) Infusion Sites

Intravenous infusions are the most common type of infusion therapy, providing a direct and rapid route into the bloodstream. The selection of a peripheral IV site is based on vein visibility, patient comfort, and the expected duration of treatment.

Peripheral Veins in the Arm and Hand

Forearm and Hand: These are the most common sites for peripheral IVs due to the accessibility and size of the veins, such as the cephalic and basilic veins in the forearm and the metacarpal veins on the back of the hand. Using the forearm can increase the dwell time and decrease pain compared to areas of flexion like the inner elbow.
Antecubital Fossa (Inner Elbow): While large and easy to access, this area is generally avoided for long-term therapy due to the high rate of mechanical obstruction when the patient bends their elbow. It is often reserved for urgent situations or blood draws.

Considerations for IV Site Selection

When choosing an IV site, healthcare providers consider the patient's medical history and vein condition. Sites to avoid include areas with:

Bruising, inflammation, or infection
Scars, moles, or tattoos, which can obscure the vein and affect absorption
Areas of flexion, like the wrist, to prevent nerve damage and discomfort
Extremities affected by mastectomy or other conditions that impair lymph drainage

Subcutaneous (SubQ) Infusion Sites

Subcutaneous infusions deliver medication into the fatty tissue beneath the skin. This route is often used for insulin, certain hormones, and hydration therapies. It is less painful than IV insertion and can be self-administered at home.

Ideal SubQ Locations

Abdomen: The abdomen is a popular and easily accessible site, offering a substantial layer of fatty tissue. Infusion sets should be placed at least two inches away from the navel to avoid potential issues.
Thighs: The outer area of the upper thighs is another effective site, offering good access and a consistent absorption rate.
Upper Buttocks and Hips: These areas have ample fatty tissue and are particularly useful for those who need to rotate sites frequently, as they are less prone to rubbing from clothing.
Upper Arms: The back or side of the upper arms is a viable option, typically between the elbow and shoulder, and is sometimes easier for caregivers to access.

Specialized Infusion Sites

For more advanced or prolonged therapy, different access routes are necessary.

Central Venous Access Devices (CVADs)

CVADs, also known as central lines, are catheters inserted into a large vein in the neck, chest, or groin, with the tip residing in a central vein near the heart. These are used for long-term infusions, administering caustic medications, or when peripheral access is not feasible.

Intraosseous (IO) Access

In emergency situations where IV access is difficult or impossible, an intraosseous infusion is a temporary solution. A specialized needle is inserted into the bone marrow, most commonly in the tibia (shin bone) or humerus (upper arm bone).

Comparison of Infusion Routes


Feature	Intravenous (IV)	Subcutaneous (SubQ)	Intraosseous (IO)
Administration Speed	Very fast; direct to bloodstream	Slower; absorbed over time	Rapid; alternative to IV in emergencies
Common Sites	Peripheral veins in arms/hands	Abdomen, thighs, upper arms	Tibia, humerus, sternum
Therapy Duration	Short-to-long-term (CVADs)	Often long-term (e.g., insulin pumps)	Short-term; emergency only (<24 hrs)
Typical Use	Hospital settings, clinics	Home therapy, outpatient clinics	Emergency medicine
Risk of Infection	Higher than SubQ; requires strict sterile technique	Lower than IV	Can occur; temporary access minimizes risk

Managing Your Infusion Site

Effective site management is essential for successful infusion therapy and to avoid complications such as infection, infiltration (fluid leaking into surrounding tissue), or phlebitis (inflammation of the vein).

Best Practices for Infusion Sites

Site Rotation: It is critical to rotate infusion sites regularly, especially for long-term therapies like insulin pumps. Using the same site repeatedly can cause scarring or lumps, which affects absorption. Patients should develop a systematic rotation schedule.
Clean Technique: Always use a clean technique during site changes to avoid infection. This includes washing hands thoroughly and using antiseptic wipes to clean the area before insertion.
Proper Adhesion: Ensure the infusion set or catheter is properly secured with an adhesive dressing or tape to prevent dislodgement, which is especially important during physical activity.

When to Contact a Healthcare Provider

Patients and caregivers should be vigilant for signs of complications. Call your clinic or infusion center if you notice any of the following symptoms at the infusion site:

Swelling, pain, or discomfort that worsens
Redness or streaks extending from the site
Blisters, bruising, or skin peeling
Pus or fluid leaking from the site
The area feels cool or pale to the touch
Fever of 100.4°F (38°C) or higher

For more detailed information on managing various infusion methods, you can visit the Cleveland Clinic website for excellent patient resources.

Conclusion

Knowing the various sites for infusion therapy and understanding the importance of proper site selection and management is crucial for a safe and effective treatment experience. Whether it's a routine peripheral IV, a self-administered subcutaneous injection, or a specialized central line, a patient's comfort and well-being are paramount. By following best practices for site rotation, hygiene, and monitoring for complications, patients can minimize risks and ensure their therapy works as intended. Always consult with your healthcare provider to determine the best site and management plan for your specific medical needs.

Frequently Asked Questions

For a short-term IV infusion, the most common sites are the peripheral veins in the arm, such as the cephalic vein, and the back of the hand. These are preferred for their accessibility and relative comfort.

For therapies requiring regular site changes, such as insulin pumps, a healthcare provider will provide specific instructions. Generally, rotating sites every 2 to 3 days is recommended to prevent tissue damage and ensure consistent absorption.

You should avoid areas with scars, moles, tattoos, or stretch marks, as these can affect absorption. Additionally, avoid placing the infusion set within two inches of the belly button or in areas with muscle movement or pressure from tight clothing.

A peripheral infusion site uses a vein in the extremities (arm or hand) for short-term use. A central infusion site, or central line, involves a catheter in a large, central vein (like in the chest) for long-term or more intensive treatments.

Signs of a problem include swelling, increased pain, redness, leaking fluid, or a warm or cool feeling at the site. Any of these symptoms should prompt a call to your healthcare provider.

It is best to avoid tattooed areas for infusion sites. The ink can make it difficult to monitor the site for signs of infection or other complications, and absorption may be affected.

Infusion sites in the lower extremities are generally avoided in adults due to an increased risk of complications like blood clots (thrombophlebitis). They are typically only used if absolutely necessary.