When a battery begins to swell it can begin to cause damage to the device itself and present the possibility of exposure to the user or technician.
Should your unit exhibit the symptoms of a swollen battery (lifting display, unit unexpectedly rebooting), Apple has authorized the replacement of the entire unit.
If the iPhone is under warranty it will be replaced for free, however if the iPhone is out of warranty Apple will replace the phone for the cost of a battery replacement. This will ensure that not only will your battery have a new lease on life, but that any damage caused to your unit will also not be an issue.
Alary Technologies can help with both these situations, please book an appointment and bring in the iPhone.
Mark W
Apple Engineer