Where does a central line go through? An in-depth guide

September 28, 2025 •

4 min read

A central line, or central venous catheter (CVC), is a medical device providing reliable access to the central blood circulation, essential for many treatments. Understanding where a central line go through is key for patients and caregivers preparing for insertion, helping to demystify the process and reduce anxiety.

Quick Summary

A central line is a flexible tube inserted into a large vein in the arm, neck, or chest, or sometimes the groin. The catheter is carefully threaded through the venous system until its tip reaches a large central vein near the heart, such as the superior vena cava. The exact entry point depends on the patient's medical needs and the type of central line being used.

Key Points

Entry and Destination: A central line enters a large vein in the arm, neck, or chest and travels to a central vein near the heart.
Purpose: Used for delivering long-term medications, TPN, frequent blood draws, and emergency care.
Types Vary by Location and Duration: Types include PICC lines (arm, medium-term), tunneled catheters (chest, long-term), and implanted ports (under skin, long-term).
Procedure Guidance: Insertion is performed under sterile conditions, guided by ultrasound or fluoroscopy, and confirmed with an X-ray.
Care is Critical: Proper hygiene, regular dressing changes, and flushing are essential to prevent infection and blockages.
Reduced Needle Sticks: Central lines minimize the need for painful, repeated needle insertions for patients needing frequent venous access.

The Journey of a Central Venous Catheter

To understand where a central line go through, it's important to know the path it takes from the entry point to its final destination. A central venous catheter is a long, flexible tube that is inserted into one of several large, accessible veins. Using imaging guidance, such as ultrasound, a healthcare provider threads the catheter through the patient's venous system. The ultimate goal is for the catheter's tip to rest in a large central vein, most often the superior vena cava, a major vessel that carries blood into the heart. This positioning allows for rapid delivery of medications and fluids, as well as easy access for frequent blood draws.

Common Central Line Insertion Sites

Central lines can be inserted through several different veins, with the choice of location depending on the patient's condition and the planned duration of treatment. The primary insertion points include:

Neck (Internal Jugular Vein): This site provides direct access to the superior vena cava and is a common choice for non-tunneled CVCs.
Chest (Subclavian Vein): Located under the collarbone, this vein is often used for tunneled central lines and ports due to its stability and reduced risk of infection compared to the femoral site.
Upper Arm (Basilic or Cephalic Vein): This is the site for a Peripherally Inserted Central Catheter (PICC), which is threaded up the arm until the tip reaches the vena cava.
Groin (Femoral Vein): This site is often used in emergency situations but is generally avoided for long-term use due to a higher risk of infection.

Types of Central Venous Catheters

The specific type of central line affects its placement and how it is cared for. There are four main types:

Peripherally Inserted Central Catheter (PICC)

A PICC line is inserted into a vein in the upper arm, and the catheter is threaded up the vein toward the heart. The external end of the catheter remains on the outside of the arm, secured with a special dressing. PICC lines are suitable for short- to medium-term treatments, typically weeks to months.

Non-Tunneled Central Catheter

This type is inserted directly into the neck, chest, or groin and is not tunneled under the skin. It is used for short-term access, usually in a hospital setting for less than two weeks, such as in emergency situations or intensive care.

Tunneled Central Catheter

A tunneled catheter is inserted into a large vein in the neck or chest and then tunneled under the skin before exiting at a separate site on the chest. This tunneling creates a barrier that can help prevent infection and provides a more stable entry point for longer-term use, lasting months or even years.

Implanted Port

An implanted port, or Port-a-Cath, is a catheter that is entirely under the skin. The catheter is connected to a small reservoir (port) that is surgically placed beneath the skin, usually in the chest. A special needle is used to access the port for medication administration or blood draws. It offers the lowest risk of infection and has fewer lifestyle restrictions for the patient.

Why is a Central Line Needed?

Central lines are used for a variety of critical medical needs, including:

Long-Term Medications: Delivering drugs like chemotherapy or extended courses of antibiotics directly into the bloodstream without repeated needle sticks.
High-Pressure Injections: Implanted ports can be used for high-pressure injections needed for CT or MRI contrast imaging.
Total Parenteral Nutrition (TPN): Providing nutrient-rich fluids to patients who cannot eat or digest food normally.
Frequent Blood Draws: Allowing for frequent blood samples to be taken with minimal patient discomfort.
Emergency Access: Providing a reliable and immediate way to administer fluids and medications during medical emergencies.

Central Line Types: A Comparison


Feature	PICC Line	Tunneled CVC	Implanted Port
Insertion Site	Upper Arm	Neck or Chest	Chest (Completely Under Skin)
Duration	Weeks to Months	Months to Years	Months to Years
Infection Risk	Low-Moderate	Low	Lowest
Daily Care	Regular dressing changes required	Regular dressing changes required	Minimal care when not in use
Access Method	External tubing	External tubing	Needle access through skin
Lifestyle Impact	Requires care during bathing; limits some activities	Requires care during bathing; limits some activities	Fewer restrictions on swimming and activities

The Central Line Placement Procedure

The insertion of a central line is a sterile procedure performed by a trained healthcare professional, often a surgeon or interventional radiologist. Here is a general overview of the steps involved:

The insertion site is thoroughly cleaned with an antiseptic solution to minimize the risk of infection.
A local anesthetic is administered to numb the area, ensuring the patient's comfort.
Using imaging guidance, the provider inserts a needle to access the chosen vein.
A guidewire is advanced through the needle, and the needle is then removed.
A dilator may be used to widen the entry site before the catheter is threaded over the guidewire and into the vein.
The catheter is advanced until its tip is in the correct position near the heart.
The line is secured, and an imaging test, such as an X-ray, is performed to confirm proper placement.

Conclusion

Knowing where a central line go through is the first step toward understanding this common medical procedure. A central line provides crucial access to the body's central circulation, allowing for the safe and efficient delivery of various treatments. The choice of insertion site and catheter type is tailored to each patient's specific needs, and proper care is essential for preventing complications like infection. For comprehensive details on central line placement and care, consult reputable sources like Johns Hopkins Medicine at hopkinsmedicine.org/health/treatment-tests-and-therapies/central-line-and-central-line-placement.

Frequently Asked Questions

The healthcare provider will use a local anesthetic to numb the area before insertion, so you should not feel pain during the procedure. Some people may feel some pressure or a mild pulling sensation, and there can be mild discomfort at the site afterward.

The most common insertion sites for a central line include a large vein in the neck (internal jugular), chest (subclavian), or arm (for a PICC line).

After the central line is inserted, a healthcare provider will use an imaging test, typically an X-ray, to confirm that the catheter tip is in the correct position near the heart.

You must keep the central line insertion site and dressing clean and dry to prevent infection. You should not swim or take baths. Your healthcare provider will provide specific instructions on how to cover the site for showering.

The duration depends on the type of central line and the patient's treatment plan. Non-tunneled lines are short-term (less than two weeks), while PICC lines can last weeks to months, and tunneled catheters or ports can last for months or years.

Potential risks include infection, bleeding, blood clots, or the line becoming blocked or dislodged. Following proper care protocols significantly reduces these risks.

A central line accesses a large, central vein near the heart, allowing for long-term use and delivery of large volumes or irritating medications. A regular, or peripheral, IV is inserted into a smaller vein, typically in the arm or hand, and is meant for short-term use.