Chronic inflammation arises in aging for a variety of reasons. Researchers focused on immune system dysfunction refer to inflammaging, a state in which the immune system is both roused and ineffective. This is in part a result of the burden of persistent infection gained across a lifetime, but also a consequence of growing numbers of senescent cells. The immune system should be removing these cells, but progressively fails at that task also. Thus immune system failure feeds upon itself, accelerating like all aspects of age-related decline. Damage causes damage.
A more subtle consequence of continual inflammation is disruption of the normal processes of tissue maintenance and regeneration. Brief and localized inflammatory signaling is a necessary part of the normal operation of regenerative processes in youthful tissues, helping to guide the intricate interactions between stem cells, immune cells, and somatic cells that is required to rebuild and repair tissue structures. Constant inflammation runs roughshod over the delicate relationships at the heart of regeneration.