Lower Back Pain After a Car Accident: When It's an Emergency, Possible Causes and Who Pays

Go to a hospital or call 911 if numbness or tingling starts just after a back injury, if you have weakness or trouble walking, or if you’ve lost bladder or bowel control. That’s from MedlinePlus, the National Library of Medicine’s health site, in its guidance on numbness and tingling.

If your lower back hurts after a car accident and you’re not sure whether it’s serious or what it will cost, that’s a hard place to be. Low back pain after a crash can come from a strained muscle, a herniated disk or a broken bone in the spine. Only a doctor who examines you can tell which. Get it checked, and mention the crash.

This guide isn’t medical advice. It shares what health agencies say.

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When is lower back pain after a car accident an emergency?

MedlinePlus’s guidance on numbness and tingling says to go to a hospital or call 911 if:

• numbness or tingling occurs just after a head, neck or back injury;
• you have weakness or can’t move, along with numbness or tingling;
• you can’t control the movement of an arm or a leg, or you’ve lost bladder or bowel control;
• you’re confused or have lost consciousness, even briefly; or
• you have slurred speech, a change in vision, difficulty walking or weakness.

If you can’t move or feel part of your body, call 911 and stay still. Someone who may have a spinal injury shouldn’t be moved unless it’s absolutely necessary, such as to escape a burning car (MedlinePlus).

Watch for changes below the waist. The nerves at the bottom of the spine are called the cauda equina. MedlinePlus says many cases of cauda equina syndrome, an injury to those nerves, are emergencies that need surgery right away. Only a doctor can tell whether you have it. As practical advice, don’t wait for an appointment if you notice new numbness or weakness in your buttocks, pelvis or legs, or a new problem with your bladder or bowels: get seen right away.

Signs of internal bleeding or shock also need emergency help: confusion, clammy skin, lightheadedness after an injury, paleness, a rapid pulse, shortness of breath or weakness (MedlinePlus).

Contact a provider right away for back pain after a severe blow or fall; weakness or numbness in your buttocks, thigh, leg or pelvis; pain traveling below your knee; pain that’s worse when you lie down or wakes you at night; severe pain that won’t let you get comfortable; redness or swelling on your back or spine; an unexplained fever; burning with urination or blood in your urine; or a history of cancer (MedlinePlus). These lists are reasons to get help, not a diagnosis. Only a doctor can tell the cause.

What can cause lower back pain after a car accident?

Back injuries can come from “a sudden jolt such as a car accident,” and the lower back is the most common site (MedlinePlus). These are possibilities to raise with a doctor, not a way to diagnose yourself:

• A strain, tear or muscle spasm. Sudden low back pain is most often caused by injury to the muscles and ligaments that support the back (MedlinePlus). See whiplash and other soft-tissue injury claims.
• A herniated disk. All or part of a disk is forced through a weak spot and can press on nearby nerves. In the lower back, it can cause sharp pain in the leg, hip or buttocks, numbness, or a weak leg (MedlinePlus). If a doctor finds one, read herniated disc injury claims.
• A broken bone in the spine. A compression fracture can cause severe, sharp pain, and trauma to the back is one cause, though osteoporosis is the most common (MedlinePlus).
• Something other than your spine. Low back pain can also come from the joint at the back of your pelvis, or from the kidneys or other organs (MedlinePlus).

X-rays can also show changes due to aging (NIAMS), so in practice a scan may show older wear next to anything new. Tell your doctor about earlier back problems.

Why can lower back pain appear later?

MedlinePlus says you’ll usually first feel back pain just after an injury or accident. It doesn’t always work that way: herniated-disk pain often starts slowly, and sometimes you don’t notice muscle weakness until a provider examines you (MedlinePlus).

For late symptoms of every kind, see delayed injury symptoms after a car accident. Whenever the pain starts, tell the doctor when it began.

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What will a doctor check for lower back pain?

Expect questions about where the pain is, how it feels and when it started. The exam may include your spine and posture, bending or lifting your legs, and your reflexes, muscle strength and sensation (NIAMS).

Most people with back pain don’t need more testing, though doctors sometimes order it to rule out or confirm a cause (NIAMS). Your provider usually won’t order spine tests at the first visit, or for 4 to 6 weeks, unless you have certain symptoms (MedlinePlus). A crash can change that: a CT or MRI may be used when there’s concern about a fracture from severe trauma, such as a car accident, or symptoms of nerve damage (MedlinePlus).

X-rays show only bones, while MRI can help show damage to soft tissues such as disks, ligaments and nerve roots (NIAMS). A herniated disk can’t be diagnosed by X-ray alone (MedlinePlus). So a visit without a scan, or a normal X-ray, doesn’t mean you weren’t hurt. Go back if the pain persists or changes.

How long might it last? For back pain in general, most people improve or recover within 4 to 6 weeks, often much sooner (MedlinePlus). Call your provider if it’s severe or hasn’t improved after three days, or if an episode lasts longer than 4 weeks (MedlinePlus). A crash injury may follow a different course, so ask your doctor.

How do you document lower back pain for a claim?

With prompt care and consistent records. The real obstacle is the claims process, which runs on paperwork: the other driver’s insurer will look at whether your injuries are directly related to the crash, so it’s in your interest to back up your claim with as much information as you can (Utah Insurance Department). These are practical habits, not legal requirements:

• Tell every provider about the crash, when each symptom began, and any earlier back problems.
• Keep a short daily note: pain level, sleep, and what you couldn’t do, such as sit through work, drive, bend or lift.
• Keep one folder for records, bills, work notes and mileage.
• Keep your follow-ups. In practice, a gap in care can give an insurer room to argue that something else caused the pain. That’s an argument, not a rule of law.
• Be ready for questions about older wear. See how to prove the crash caused your injury.

Hold off on signing a release until you know how badly you were hurt: Utah’s insurance department, for one, warns that it means the amount offered is the only amount you will ever receive from the other driver and their insurer. See what to say when an insurance adjuster calls and how to preserve evidence after an accident.

Who pays for lower back treatment after a car accident in Michigan?

Usually your no-fault auto coverage, whoever caused the crash, though your policy may have a medical limit or an opt-out. Elsewhere, it depends on your state and coverage; see who pays your medical bills while your claim is pending.

What to do next

1. Call 911 or go to a hospital for any danger sign above. Otherwise, see a doctor promptly and say you were in a crash.
2. Report changes, especially numbness, weakness, or anything new with your bladder or bowels.
3. In Michigan, send your auto insurer written notice well inside one year of the crash.
4. Get advice before you sign a release or give a recorded statement. Get a free case review, or compare Michigan injury lawyers near you, and get any fee agreement in writing.

What waiting can cost

• Your health. With a spinal cord injury, the time between injury and treatment can affect the outcome (MedlinePlus).
• Your benefits. Without written notice or a payment within one year of the crash, a lawsuit for PIP benefits can be barred (MCL 500.3145(1)).
• Your claim. Michigan’s general three-year deadline to sue runs from the injury (MCL 600.5805(2)).

What a good outcome looks like

Your back gets checked, your records show the crash and how you healed, PIP pays what it owes, and you settle only once you know how badly you were hurt. From wondering whether a sore back after a wreck matters to knowing it’s been checked, written down and inside every deadline.

For more, see our checklist of 10 things to do after a car accident, recovering after a car accident and the car, truck and motorcycle accident guides.

Updated November 11, 2026

This guide is general information, not legal advice, and laws change. For advice about your situation, talk to a lawyer licensed in your state. Reading this page or contacting us does not create an attorney-client relationship.