A simple way to think of trauma is as distress that remains with one's identity. Regardless of when the distress happened, it is–for any number of reasons–staying with the identity and metabolizing itself as the 5 bodies (see secondmindmedicine.com/anatomy for a description of the 5 bodies).
"Metabolizing itself" means that the distress is a pattern that is going through its life cycle from birth to death, just as any entity or object has a time it at which it begins and ends. This means that trauma, even when it appears stagnant and lodged in the body, is moving, even if it's not moving on fast enough.
Imagine a gust of wind metabolizing itself: It starts as a gentle movement of air, picks up strength, becomes solid-like and strong, then eventually loses its momentum and de-patterns itself unto air. Similarly, stress becomes distress–a patterning that continues in-forming our identity as the 5 bodies. It lives as the physical, mental, energetic, and informational bodies. Consciousness alone–the root of what we are, the deepest body–remains as it is, noting its modifications as the other bodies.
The beautify of this recognition is that trauma is not something that happened in the past; it is a patterning that is happening now. Because this is true, trauma is always fully available for undoing by exploring the integrity and patterning of our bodies. Seen this way, trauma work is the work of walking with ourselves as we are, and perhaps over the journey, seeing ourselves for the first time.