I have a line of a couple inches across my left ribs of spider veins. they are faint and not very obvious. just barely noticing them. causes?

Unusual site: In a young male, SV in the area described is unusual. These may be normal reticular veins especially visible in those with light complexion. In some who have advanced liver disease, one might see spider angioma. These may be seen as a benign process in young adults; more that five suggests liver disease.

Spider Veins: The cause of spider veins in often uncertain. Although they most often form on the legs, they can arise on any part of the body skin. It may be possible that you traumatized that area at some point in the past and the body could be responding by forming the spider veins in the skin in that area. It may be hard to know for certain why they formed in that location.

Straining or trauma: Spider veins are dilated capillaries in the skin. They're most common in the legs and are from the veins stretching out over time. On the chest they can be from straining (coughing, heavy lifting, e.g.) or some trauma to that area in the past. If they're very faint, they're probably of no medical concern. They can be treated with sclerotherapy or laser to improve the appearance.

Hmmm: Hard to say. Sometimes they can stem from a simple bruise or injury.