Why has a blue blood vessel appeared on my upper lip?

"G.O." Syndrome: Aha, it's due to the "G.O."syndrome. Skin thins, subcutaneous fat decreases, venous valves relax, veins thin, facial structures sag a bit, wear and tear.I'm sure you understand.If it really bothers you you could see a plastic surgeon.They might offer laser,injections,intense pulsed light,etc. In the meantime maybe use makeup,a hat with laced veil, or a fake moustache.It ain't fun Gettin' Old!