Brachiocephalic Vein

Your brachiocephalic vein helps return oxygen-poor blood from your head, neck and arms back to your heart. It’s a paired vein, meaning you have one on each side of your body (right and left). Each brachiocephalic vein begins at the place where your subclavian vein and internal jugular vein meet.


What is the brachiocephalic vein?

Your brachiocephalic vein, also called your innominate vein, is part of the circulatory system in your upper body. It’s a paired vein, meaning you have one on each side of your body. These veins are called your:

  • Right brachiocephalic vein.
  • Left brachiocephalic vein.

Your right and left brachiocephalic veins play an important role in helping oxygen-poor blood flow from your upper body to your heart.


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What is the function of the brachiocephalic vein?

Your brachiocephalic veins carry oxygen-poor blood from your head, neck and arms back to your heart. These veins are short segments of a much larger system of veins that carry blood throughout your upper body. But those short segments are vital for the whole system to work properly.

Imagine a long pipe with many parts that connect to each other. If you remove one of the parts in the middle, nothing can flow through the pipe anymore. Similarly, your body’s veins all connect together to keep your blood flowing in the correct direction. Each vein helps your blood move along and get where it needs to be.

Here’s how your brachiocephalic veins fit into the picture. Your right and left brachiocephalic veins merge to form your superior vena cava. This large vein is located above your heart, and it extends downward to drain blood into your right atrium (top right heart chamber).

From there, your blood flows through the right side of your heart and into your lungs to gain oxygen. Your blood then returns to your heart, and your left ventricle pumps it out to your body.

So, your brachiocephalic veins help your blood move through your heart and lungs, and ultimately through your whole body.


Which veins form the brachiocephalic vein?

Your subclavian vein and internal jugular vein join together to form your brachiocephalic vein. This union happens on each side of your body (right and left).


Where is the brachiocephalic vein located?

Your brachiocephalic veins are deep veins on each side of your upper chest. They’re below your collarbone (clavicle), not far from your shoulders. Here’s where they begin:

  • Right brachiocephalic vein: Where your right subclavian vein and right internal jugular vein meet.
  • Left brachiocephalic vein: Where your left subclavian vein and left internal jugular vein meet.

Your right brachiocephalic vein travels vertically down toward your heart.

Your left brachiocephalic vein is longer in length, and it takes a more scenic route. It travels horizontally, at a slight downward angle, to meet your right brachiocephalic vein. Along the way, it passes above your aortic arch and in front of your carotid arteries. It then joins with your right brachiocephalic vein. That union marks the start of your superior vena cava.

Which veins drain into the brachiocephalic vein?

Many veins drain into your brachiocephalic veins, including your:

  • Internal jugular veins.
  • Subclavian veins.
  • Left and right inferior thyroid veins.
  • Left and right internal thoracic veins (also called internal mammary veins).
  • Left and right vertebral veins.
  • Left superior intercostal vein.

All of these veins carry oxygen-poor blood that needs to return to your heart.


How big is the brachiocephalic vein?

Your right and left brachiocephalic veins are different sizes. Your right brachiocephalic vein is about 2 to 3 centimeters long. To picture this length, think of two aspirin pills placed side by side. The length across both pills is almost 3 centimeters.

Your left brachiocephalic vein is longer, measuring about 6 centimeters.

What is the brachiocephalic vein made of?

Like your other veins, your brachiocephalic veins are made of three layers of tissues and fibers:

  • The tunica adventitia (outer layer) gives structure and shape to your vein.
  • The tunica media (middle layer) contains smooth muscle cells that allow your vein to get wider or narrower as blood passes through.
  • The tunica intima (inner layer) has a lining of smooth endothelial cells, which allow blood to move easily through your vein.

Unlike many of your other veins, your brachiocephalic veins don’t contain valves.

What anatomical variations affect the brachiocephalic vein?

Some people are born with anatomical variations that affect their brachiocephalic veins. The most common variation is a retroaortic brachiocephalic vein. This means your left brachiocephalic vein passes below your aortic arch, instead of above it. As a result, your vein travels behind your ascending aorta (the first part of your aorta), rather than in front of it like it usually does.

Brachiocephalic vein variations affect about 1 in 250 babies. If the variations occur on their own, they’re usually harmless. But often they occur in babies who also have some form of congenital heart disease (CHD), including:

In about 60% of cases, the associated CHD is mild. But some babies have more severe forms of CHD that need treatment or surgery.

Brachiocephalic vein variations become important if you need certain surgeries or procedures, such as:

  • Connection to cardiopulmonary bypass (heart-lung machine).
  • Insertion of a pacemaker.

That’s because these procedures could affect your brachiocephalic veins or surrounding areas. So, your provider may run imaging tests before your procedure to check your anatomy. They’ll make adjustments as needed during your procedure.

Conditions and Disorders

What conditions affect the brachiocephalic vein?

Conditions that could affect your brachiocephalic vein include:

  • Complications from a central venous catheter. Healthcare providers often use your brachiocephalic veins for central venous access. This means they insert a thin, flexible tube into your vein to provide something your body needs (often fluids or medications). Complications can include a perforation (hole) in your vein or upper extremity deep vein thrombosis. Rarely, pseudoaneurysms can also form.
  • Stenosis (narrowing). Some medical interventions can cause your vein to narrow. For example, if you’re on dialysis, your provider may create an arteriovenous fistula. This is a connection between an artery and a vein that helps with dialysis access. It often involves your brachiocephalic vein. Vein stenosis is sometimes a complication.
  • Tumors. Growths in your chest can press on your vein and interfere with blood flow. The tumors may form in your chest (primary mediastinal tumors). Or, they may spread from somewhere else in your body (as in metastatic breast cancer).

What tests do providers use to check the brachiocephalic vein?

Your provider may use the following tests to check your brachiocephalic veins for tumors or other problems:


How can I keep my brachiocephalic vein healthy?

Practicing a heart-healthy lifestyle can help all your blood vessels, including your veins, function at their best. Some tips include:

  • Avoid smoking and all tobacco products.
  • Drink lots of water.
  • Eat a heart-healthy diet. This can help lower your blood pressure, cholesterol and body weight.
  • Go for walks. Try to walk for 30 minutes at least five days a week. Be sure to check with your provider before starting a new exercise routine.
  • Move around during the day. Taking short movement breaks keeps your blood moving throughout your body.

A note from Cleveland Clinic

Your brachiocephalic vein is an important part of your circulatory system. It helps oxygen-poor blood from your upper body return to your heart. So, it’s important to do whatever you can to keep your brachiocephalic vein and all your veins in good working order.

Practicing heart-healthy habits can help your veins function well for many years to come. Talk with your provider about changes you can make in your daily life.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 07/08/2022.

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