In Jodi Picoult's "My Sister's Keeper," the concept of relationships is likened to living entities, emphasizing their complexity and necessity for nurturing. The analogy suggests that every relationship has essential components that contribute to its overall health. When minor issues arise, such as the metaphorical loss of a fingernail, it might be manageable. However, when significant aspects, like the heart, are missing, it fundamentally alters the dynamic and health of the relationship.

This highlights the importance of addressing serious issues within personal connections. Just as a heart is vital for life, critical elements in relationships must be tended to for them to thrive. The quote illustrates that relationships require careful attention and care, especially when facing significant challenges that threaten their very existence.