There are two doors after a crash in this city, and they are not in competition. One is an emergency department, open all night, built to rule out the things that kill or paralyze. The other is an injury clinic, open business hours, built to examine, diagnose, and plan care for the things that hurt and linger. Most people need one of them. Some people need both, in that order. Almost nobody needs neither.
This page draws the line between them as clearly as a publication can without examining anyone. When in doubt, pick the emergency door. A clinic will always be there on Monday.
The emergency door, tonight
Chest pain, a sudden severe headache, weakness or numbness on one side, trouble speaking, a loss of bowel or bladder control, or a head injury with vomiting or worsening confusion is an emergency room trip right now, not a call to a clinic.
Add to that list: any crash where you lost consciousness even briefly; a headache that is getting worse by the hour; repeated vomiting; a seizure; one pupil visibly larger than the other; a person who is hard to wake or who is behaving in a way the people around them do not recognize; severe pain in the neck or back with any weakness, numbness, or tingling in the arms or legs; an inability to bear weight; deep cuts; and any pregnancy with abdominal pain or bleeding after a collision. The Centers for Disease Control and Prevention publishes danger signs for head injury in adults and children, and they are worth reading once, tonight, before you need them (CDC, HEADS UP signs and symptoms).
An ER visit does not replace the injury exam. It rules out the worst, often with imaging, and discharges you with instructions to follow up. The follow-up is the clinic's job.

The clinic door, this week
Everything else that hurts after a crash and is not on the emergency list belongs in a planned exam within the week: neck stiffness and pain, headaches that are steady rather than worsening, low back pain, shoulder or hip pain from a belt or a door, the fog and screen trouble of a probable concussion, dizziness that comes and goes, sleep that has gone wrong since the crash. Those are the injuries that improve with a plan and get worse with a month of guessing.
Missouri Injury Clinic publishes the auto injury lane as diagnosis and a treatment plan after a crash, and the TBI and concussion rehab lane alongside it. The first visit is history, exam, findings, and a written plan. The first visit describes it in full.
Both doors, in order
The common sequence in the river city goes like this. A crash on I-64 at rush hour. An ambulance ride or a self-drive to an ER, because the headache scared someone. A scan, a clean read, a discharge with instructions to follow up. Then nothing, because the discharge paper said follow up and did not say where, and the neck felt better by the weekend.
The neck came back on Tuesday. That is the gap this desk is built to close. The ER did its job; it ruled out the emergency. The exam that writes down the neck and the headache and the plan for both still has to happen, and the week after the crash is when it does the most good. Bring the ER paperwork with you. It becomes part of the record.
What a clinic should do if you walk in with an emergency
Send you out. An injury clinic is built for planned care, and a front desk or a clinician who tells you to go to an emergency room instead of booking you is the system working, not a wasted trip. Do not take it as a rejection. Take it as a reading.
The rooms, for the clinic door
Tesson Ferry for the south side, Hazelwood for the north county, O'Fallon for the west. Hours are business hours, with a midday close from 12 to 2 every day. None of the three is an emergency facility and none should be called as one. Three rooms across the metro has the addresses and phones.
Educational only. Nothing on this page is medical advice or a diagnosis; a licensed clinician who has examined you is the person to ask. Facts about the clinic come from moinjuryclinic.com. Emergency symptoms go to the emergency room, not to a clinic or a website.