Hello and welcome to HCM
The chest contains a large number of structures like ribs, lungs, soft tissues, blood vessels, nerves, heart, etc.
Swelling below the left
clavicle can be due to pathology of ribs, lung, vassels or nerves.
Association of the swelling with
shortness of breath, pain and heaviness of the left arm definitely requires a CT chest.
Involvement of nerve plexus- compression or a
tumor arising from the swelling is a possibility at your age.
However, if associated with other constitutional symptoms like
weight loss, loss of appetite points towards more serious pathology like a malignancy of the lung.
But nothing can be confirmed without investigations.
Consult your physician at the earliest for investigations and management.
Thank you and take care
Dr Shailja P Wahal