What does it mean when your vigina is swollen and it doesn't hurt?

Yeast? Allergy?: It would be unusual for the vaginal area, labia, etc to swell up without also being itchy, painful, or irritated. Possibilities that come to mind include yeast infection, genital herpes, chemical irritation (e.g. from spermicide?), allergic reaction, e.g. to a drug, perfume, or laundry detergent. All these usually would hurt or be irritated, but sometimes not. Get care if it doesn't clear up soon.