My labia minora (left) is swollen. Its been there for a week. There is no discomfort from it.. no pain, itching or any symptom. What is the reason for this and how can it go?

That is odd. It is hard to say what it could be. It could be friction if your Labia tend to extend beyond your vulva, but that shouldn't be anything new. Have you used any new detergents or soaps or anything like that.

I would see your OB.GYN about it. Could be an infection.