How Is A Blood Clot Of The Arm Diagnosed?

A blood clot in the arm is diagnosed with an ultrasound.  The ultrasound uses sound waves to look at the body.  There is no radiation.  An ultrasound is done by a technologist who is specially trained in the field.  The test is interpreted by a radiology doctor.

What veins does the test look at?

The test looks at the major veins of the arm.  This starts with the jugular vein in the neck.  The subclavian, axillary, brachial, cephalic, basilic, radial and ulnar veins are examined with ultrasound.

How is the test done?

The technologist will demonstrate blood flow in the veins.  They will compress the veins.  A vein which compresses completely will not have a clot in it.  The technologist may also squeeze a part of your arm at times.  This will increase blood flow to the vein.  This is another sign of no clot being present and is called augmentation.

What do we see with a clot?

A clot in one of the veins will prevent the vein from being compressed.  There is usually decreased blood flow as the blood can not pass through the clot.   Blood flow will not usually be increased when the arm is squeezed.

Why is a clot in the arm dangerous?

A blood clot in the arm may be associated with pain and swelling.  A blood clot in one of the deep veins of the arm can be dangerous because it can go to the lungs.  A blood clot going to the lungs can result in chest pain and shortness of breath.  Blood clots to the lungs are diagnosed with CT.

An ultrasound exam of the arms will also look at the tissues around the veins.  Sometimes we see bleeding or other fluid collections.  We sometimes identify enlarged lymph nodes next to the vein.  We also often see swelling of the arm.

Blood clots of the deeper veins like the subclavian, axillary and brachial veins are more dangerous as they have a higher risk of going to the lungs.  Clots in these veins will often be treated with blood thinners.

Blood clots in the veins are diagnosed with ultrasound.  This is a quick test which uses no radiation.  We can also occasionally diagnose unrelated conditions like swelling, fluid collections, bleeding and enlarged lymph nodes.