Why the emergency department cleared you

The job in the first hours is to rule out fracture, cord injury, internal bleeding and organ damage. A normal CT and a discharge sheet mean those were excluded, which is genuinely reassuring and frequently misread as meaning nothing is injured.

Facet capsular injury, sacroiliac ligament injury and annular tears are all invisible on the imaging used for trauma triage. They are also the injuries most likely to still hurt months later. So a clean scan and persistent pain are not a contradiction; they are the normal presentation of a soft-tissue spinal injury.

Why it often gets worse before better

Adrenaline and the acute stress response suppress pain perception at the scene. As that resolves over twenty-four to seventy-two hours, inflammation in the injured tissue is peaking. That is the day-three phenomenon, and it is physiology rather than exaggeration — though it is frequently treated as the latter, particularly when a claim is involved.

What actually gets injured in a rear-end impact

• Facet joint capsules, from rapid extension then flexion. The most common source of persistent post-collision axial pain. Facet syndrome.
• Sacroiliac ligaments, particularly with a braced leg on the brake at impact. The SI joint.
• Annular tears, from the shear across the disc.
• Nerve root irritation, if a herniation results. Radiculopathy.

What we would do differently at four months

Stop repeating trauma imaging, which has already answered its question, and start asking which structure is generating pain now. That is examination plus, where indicated, a diagnostic block. Facet-mediated pain after a collision is common and it responds durably to radiofrequency neurotomy once confirmed.

Documentation matters here in a way it does not elsewhere, and we treat that as part of the clinical work rather than an administrative afterthought. A record that names a structure, states how it was tested and tracks function over time is both better medicine and a more honest account than one that says the patient continues to report pain.

Common questions

Why did my pain start days later?

Acute stress response masks pain at the scene, and tissue inflammation peaks over the following two to three days. It is the expected pattern, not a suspicious one.

My scans were normal. Does that mean I am fine?

It means fracture and serious structural injury were excluded, which matters. It does not exclude the soft-tissue injuries that most often cause lasting pain, because those do not appear on those scans. What imaging can and cannot show.

How long should this take to settle?

Most collision-related back pain improves substantially over weeks to a few months. Pain unchanged at three to four months deserves a structural answer rather than more time.

Related reading

• Lumbar facet syndrome
• Sacroiliac joint pain
• What your MRI actually showed
• Red flags