You might consider a breast lift if
1. Your breasts sag — they've lost shape and volume i.e. they look flat and droopy
2. Your nipples — when the breasts are left unsupported — fall below your breast creases
3. Nipple and areolae point downward
4. The areolae have stretched out of proportion to your breasts
5. Significant asymmetry of the breasts with one breast very droopy.