Early symptoms of varicose veins?

Are there any warning signs before varicose veins?

Sometimes, when I sit and then stand up... my feet feel numb, and they turn red or purple.

Could this also be related to varicose veins? ㅜ

I just thought it was because I sat for a long time and it caused numbness...

Is it better to just leave it untreated or should I at least visit a local clinic? Or should I go to a larger hospital?

Can varicose veins occur at a young age?