Why Does Juvederm Leave a Bump After the Injections?

When dermal fillers are injected the material expands the surrounding tissue. This is normal, and may cause some raising of the skin surface.
Over a few days this subsides to a flatter surface, while maintaining the cosmetic improvements for the life of the filler. The duration of the filling effect will vary with the type, location, and volume of filler used.

The technique that is used to inject the juvederm is what is resulting in the lumpines or bumps.  The skill of the injector is very important.  Make sure that the person injecting the Juvederm is a board certified plastic surgeon. Nurse injectors just do not have enough skill, training, education, or expertise to inject fillers.

Some patients develop a small skin bump right after the injection because that's how their body responds to a skin injury (from the needle) and goes away in a day and is unrelated to the filler.  Other times, the bump can occur as a result of too much product in that area.  Gentle massage over time will make this better.  Juvederm is a very cohesive filler and can 'clump' sometimes.  Ask for a less cohesive filler next time and let your provider know about the bump so they can alter their technique to avoid too much product in an area. 

This little bump is usually caused by the injection process, due to the needle piercing the skin. It goes away in the day or two after your treatment. A gentler injection technique can be performed to reduce the size of this bump.

It’s not unusual for small bumps to occur following Juvederm
injections. These bumps occur at the
site of the injection and are related to the injection technique. When Juvederm is injected close to the
surface of the skin these bumps commonly occur. They can be prevented by avoiding superficial injections. Once they occur, they can be treated with
massage. In most cases, a response is
generated within a week following this maneuver. If
you’re concerned about this problem you should consult your physician. Your physician should be able to make an
appropriate recommendation.

I don't usually get any bumps with the injection. If placed too superficial, irregularities can occur. If the bump is not gone in a few days then I would question the injection technique.