A central claim of trauma research, and the one that gives Bessel van der Kolk's book its title, is that unprocessed psychological distress frequently manifests as physical symptoms — not as a metaphor, but as an actual physiological process. Chronic pain, autoimmune flare-ups, and respiratory symptoms can be directly tied to unresolved emotional distress rather than (or in addition to) purely physiological triggers, which means treating the physical symptom alone, without addressing the underlying trauma, often leaves the root cause completely unaddressed.
This has real implications for how physical symptoms without a clear organic cause get treated: dismissing them as "not real" once no physiological cause is found misses the point entirely — the body is registering something real, it's just not something a purely physical examination is built to find.