What is a chicken's lifespan?

Can you please elaborate on the typical lifespan of a chicken? Are there any factors that can influence the duration of a chicken's life, such as breed, diet, or living conditions? Also, are there any common health issues that chickens face as they age, and how can these be prevented or managed? Understanding the intricacies of a chicken's lifespan is crucial for proper care and management, so I'd appreciate your insights on this matter.