Is This Normal Side Incision Healing? Breast Reduction 18 Days Post Op. (photo)

If you have concerns about your incisions, I would advise addressing them with your plastic surgeon. It is very common to see delayed healing after breast reduction surgery. Dressing changes are the best way to handle any open areas. Even though these areas can be small, they can take awhile to heal. I would follow whatever your doctor recommends for wound care. I usually follow patients with delayed healing at least once per week. If the final scar ends up being wide or depressed, scar revision is always an option after the scar is mature at 1 year post-op.

It is on the low side of normal. Best to have very close follow up with your chosen surgeon. There you can have aggressive wound care. 

It appears that you are healing normally but if you have any problems then you should check with your plastic surgeon.  He is in the best position to understand if you are having problems and to direct your healing progress.