Axillary Artery

What is the axillary artery?

Your axillary artery is a blood vessel that runs through your armpit and delivers oxygen-rich blood to your upper limb. It’s a continuation of your subclavian artery. Once it’s below your shoulder blade, it becomes your brachial artery. You have two axillary arteries — one on each side of your body. These are called your right axillary artery and left axillary artery. They both play an important role in supporting normal blood flow in your upper body.

What does the axillary artery do?

Your axillary artery supplies blood to your upper arm. This blood contains oxygen and nutrients that nourish your tissues. That’s an important job. Your muscles, bones and other parts of your arm need a constant supply of blood. This helps them stay healthy and work as they should.

Your axillary artery has other functions, too. But these aren’t ones you need every day. Rather, they become important when you receive medical care.

For example, this artery can serve as an access point when healthcare providers connect you to a heart-lung machine. Your provider inserts a thin tube called a cannula into the artery. This allows oxygen-rich blood from the machine to return to your body while you’re in surgery.

Where is the axillary artery located?

Your axillary artery is nestled inside your armpit area. It follows this course:

• Starts at your first rib, just below your collarbone
• Travels down through your armpit
• Ends in your upper arm, at the base of your shoulder blade

Another blood vessel, the axillary vein, runs next to your axillary artery. This vein carries oxygen-poor blood back toward your heart. That means blood in the axillary vein and the axillary artery travel in opposite directions. To picture this, imagine cars on a two-lane road.

Your axillary artery isn’t close to the surface of your skin. It’s deeper within your chest muscles. A bundle of nerves called the brachial plexus intertwines with the artery along its course.

What are the axillary artery branches?

Your axillary artery has several branch arteries. These vessels start at various points along your axillary artery. Then, they travel off in another direction. They carry blood to different areas of your chest, shoulder, armpit and upper arm. You can think of these like limbs on a tree, or side streets connecting to a main road.

Your axillary branch arteries include:

• Superior thoracic artery
• Thoraco-acromial artery
• Subscapular artery
• Anterior/posterior circumflex humeral artery
• Profunda brachii artery (in some people, this branches from the brachial artery instead)

What conditions can affect the axillary artery?

The most common conditions affecting your axillary artery are injuries to nearby bones. The bones may press on or poke through the artery. This can lead to internal bleeding and blood clots. The injury can also disrupt blood flow in your arm. If this happens, your arm may look paler than usual or feel cold to the touch.

Specific injuries that may damage your axillary artery include:

• Humerus fracture: This means your upper arm bone is broken.
• Dislocated shoulder: This is when something pushes the bones in your shoulder joint out of place.
• Penetrating trauma: Sharp objects that cut your arm may damage your axillary artery.

Seek medical care right away if you think you’ve broken a bone or if you experience a traumatic injury.

Rarely, axillary artery damage can occur as a complication of surgery, like shoulder replacement surgery.