There are three general types of thoracic outlet syndrome: 
Neurogenic (neurologic) thoracic outlet syndrome. This most common type of thoracic outlet syndrome is characterized by compression of the brachial plexus. The brachial plexus is a network of nerves that come from your spinal cord and control muscle movements and sensation in your shoulder, arm and hand.
Venous thoracic outlet syndrome. This type of thoracic outlet syndrome occurs when one or more of the veins under the collarbone (clavicle) are compressed, resulting in blood clots.
Arterial thoracic outlet syndrome. This is the least common type of TOS. It occurs when one of the arteries under the collarbone is compressed, resulting in bulging of the artery, also known as an aneurysm.
 It's possible to have a mix of the three different types of thoracic outlet syndrome, with multiple parts of the thoracic outlet being compressed. Thoracic outlet syndrome symptoms can vary depending on the type. When nerves are compressed, signs and symptoms of neurogenic thoracic outlet syndrome include: 
Numbness or tingling in your arm or fingers
Pain or aches in your neck, shoulder, arm or hand
Weakening grip
 Signs and symptoms of venous thoracic outlet syndrome can include: 
Discoloration of your hand (bluish color)
Arm pain and swelling
Blood clot in veins in the upper area of your body
Arm fatigue with activity
Paleness or abnormal color in one or more fingers or your hand
Throbbing lump near your collarbone
 Signs and symptoms of arterial thoracic outlet syndrome can include: 
Cold fingers, hands or arms
Hand and arm pain
Lack of color (pallor) or bluish discoloration (cyanosis) in one or more of your fingers or your entire hand
Weak or no pulse in the affected arm
