Life-Threatening Lower Back Pain – Decoding the Mystery Step-By-Step
SOURCE: A Chiro.Org Contribution
David J Schimp DC, DACNB, DAAPM, FICCN and
Stefanie Krupp DC, MS
David J Schimp DC
Schimp Office of Chiropractic Professionals LTD
937 E. Sumner St.
Hartford, WI 53027 USA
This article will help clinicians identify life-threatening conditions that present with lower back pain.
Intra-abdominal bleed (e.g. aortic aneurysm), infection and tumor are the most dangerous causes of lower back pain and carry the potential for devastating consequences.
Table 1 identifies red flags that should raise suspicion of a serious disorder. 
Other red flags that are less likely to be associated with a life-threatening condition but that still warrant prompt diagnosis and appropriate management include:
- pain that is worse with coughing
- incontinence of bowel or bladder
- urinary retention (inability to void or empty the bladder completely)
- saddle anesthesia
- intractable radicular pain into the lower extremity
- rapidly progressive neurological deficit
The latter findings are common among patients with lumbar nerve root compression or cauda equina syndrome. Although serious, these disorders are seldom life threatening.
Step 1 – Evaluate for Red Flags*
Table 1: Red Flags of Low Back Pain 
|1. Duration greater than 6 weeks|
|2. Age less than 18y|
|3. Age greater than 50y|
|4. Prior history of cancer|
|5. Fever, chills or night sweats|
|6. Weight loss (unexplained)|
|7. IV drug use|
|8. Recent surgical procedure|
|9. Night pain|
|10. Unremitting, constant, no relief|
|11. Concomitant abdominal pain|
|12. Lightheaded, weak, diaphoretic, disorientated|
* This is a list of red flags that may be associated with a life-threatening disease.
It is not meant to include all the other red flags of lower back pain.
Step 1: Evaluate for Red Flags (Discussion)
- Duration greater than 6 weeks. Intractable or progressive lower back pain lasting longer than 6 weeks should raise suspicion of a serious underlying condition. Radiographs (lumbar plain film series including coronal, sagittal and spot views) and routine laboratory studies will add a greater level of diagnostic accuracy to the evaluation. Basic laboratory studies to consider include comprehensive metabolic panel, complete blood count (CBC), C-reactive protein(CRP) or high sensitivity CRP (preferred), erythrocyte sedimentation rate (ESR) and urinalysis (UA). If imaging and lab studies are normal and the patient has normal vitals, then serious disease is unlikely. Advanced imaging (MRI or CT) can be utilized if plain film radiography if felt to lack sensitivity. In the absence of serious disease, a mechanical lesion, central sensitization or psychosocial co-morbidities may explain on-going pain over 6 weeks in duration.
- Age less than 18 years. Persistent pain in a pediatric patient is a red flag for tumor or infection if symptoms cannot be ascribed to a congenital abnormality or acute injury. Advanced imaging (MRI) and routine laboratory studies as noted above should be considered.
- Age greater than 50 years. Although low back pain is common in this population, clinicians should be particularly alert to the patient that presents with a new onset of low back pain, whether or not a mechanical basis is identified. Intra-abdominal disorders (e.g. abdominal aortic aneurysm) and cancer are more common in this population. Although a mechanical lesion is more likely, older patients require a greater level of diligence to rule out serious disease.(see Table 1)
- Patient history of cancer. Neoplasm involving the spine may present as unrelenting pain (i.e. does not improve with rest or analgesia) or pain that is worse at night. Cancer recurrence or metastasis to the spine should be considered when a patient with a prior history of cancer complains of unrelenting back pain. Advanced imaging (MRI) is valuable and early use may be appropriate if the index of suspicion is high. Basic laboratory testing can be helpful (e.g., elevation of alkaline phosphatase on a comprehensive metabolic panel and leukocytosis on a complete blood count).  A history of prior malignancy is the most informative of the all the red flags listed in Table 1 and may suggest active neoplasm as the cause of the individual’s back pain.
- Fever, chills or night sweats. Vertebral osteomyelitis or spinal epidural abscess should be ruled out with advanced imaging when a patient with back pain also experiences fever, chills or night sweats. Basic laboratory evaluation (CBC, ESR and CRP or high sensitivity CRP) may confirm the presence of infection. [2, 3]
- Weight loss (unexplained). Weight loss or anorexia accompanied by back pain is a potent warning sign that suggests malignancy. Radiographs and basic laboratory studies are indicated if weight loss cannot be attributed to loss of appetite secondary to stress (e.g. bereavement). Laboratory evaluation should include fasting blood glucose, hemoglobin-A1c (HgA1c) and basic thyroid hormone assessment (TSH, Free T3 and Total T4) to rule out diabetes and hyperthyroidism.  Although not as common as weight gain, some patients with type 2 diabetes may actually lose weight. This is because the inability to metabolize glucose for fuel induces a cachexic state because the body uses alternative fuels stored in muscle and fat.
- IV drug use. IV drug use poses a risk for infection. If identified during the patient history then a complete blood count is indicated to evaluate for the presence of leukocytosis.
- Recent surgical procedure. Post-surgical infection can develop any time from 2-3 days after surgery until wound healing is complete (2-3 weeks following the surgery). Persistent pain developing during this period should raise immediate concern for infection. Laboratory evaluation (CBC) may reveal leukocytosis. Referral to the attending surgeon is warranted if infection is confirmed (referral may be prudent even if laboratory evaluation is normal).
- Night pain. Nocturnal back pain that is not relieved despite positional change suggests a serious underlying disorder and warrants investigation utilizing radiography and basic laboratory studies including total prostate specific antigen (PSA) in men.  If night pain is associated with fever, then infection is possible. If fever is absent, malignancy is a stronger consideration.Sometimes mechanical pain can disrupt sleep. For example, a patient with acute lumbar radiculopathy may not be able to sleep because of persistent nerve root irritation (i.e. disc protrusion or lumbar spondylosis) causing radiating leg pain. This is not a life-threatening situation.
- Unremitting, constant pain (no position affords relief). Patients with mechanical pain are usually able to find a palliative position. When no position brings relief, the index of concern is elevated and serious disease must be considered. If the patient is unstable, (i.e. vitals are abnormal) then urgent medical care is appropriate to rule out a vascular disorder (e.g. aneurysm). If the patient is stable, and consents to conservative management, then the initial diagnostic work-up should include physical examination, radiography and basic laboratory studies.
- Concomitant abdominal pain. The presence of abdominal pain with lower back pain suggests a potentially serious disorder. As above, if vitals are abnormal and the patient is unstable, then urgent referral to rule out a vascular lesion is recommended. If the patient is stable, then the initial diagnostic work-up should include physical examination, radiography and basic laboratory evaluation. Additional lab tests to consider include serum lipase and amylase and total PSA in men.The physical examination should include evaluation for the following:
- bounding abdominal pulsation
- abdominal bruit
- peripheral lower extremity edema
- Lightheaded, weak, diaphoretic, disorientated. These findings are suggestive of hypovolemia or vascular collapse. Aneurysm or aneurysmal rupture must be urgently considered when these symptoms are associated with back or abdominal pain. Urgent referral utilizing emergency medical services is warranted.
DO NOT ATTEMPT TO TRANSFER. CALL 911.
Step 2 – Screen for a Life-Threatening Condition (Table 2)
|1. INTRA-ABDOMINAL BLEED
Patient >50yoa, family history, known vascular disease, smoking history >100 life-time cigarettes.
|Patient is diaphoretic, pale or weak. Bruising discoloration of the peri-umbilical region or flank. Lower extremity cyanosis or blue toe.* Acute pain||Hypotension (<90mm Hg systolic or >40mm Hg below baseline), tachycardia (>100bpm), abdominal bruit, wide bounding abdominal pulsation or thrill. Sp02 <95%||Urgent referral. CT angiography is the gold standard of diagnosis. Abdominal ultrasound appropriate for monitoring or when CT not available.|
Recent illness or surgical procedure, penetrating tissue injury or IV drug use.
|Patient is acutely ill with extreme pain and when condition is in later stages patient does not want to be touched or moved.||Fever, point spinal tenderness (percussion), erythema, purulent drainage from region, swelling and/or, warmth. No clear mechanical pattern on orthopedic exam.||Complete blood count reveals elevated WBC and neutrophils in acute bacterial infection. ESR and CRP elevated. Urinalysis may reveal blood, WBC or bacteria. MRI appropriate.|
|3. TUMOR History of breast, lung, thyroid, kidney, colon or prostate cancer, myeloma, lymphoma or sarcoma.||Variable. May be stable with isolated back pain or present with new and/or progressive neurological compromise.* Evaluate for lower extremity edema.||Gait disturbance, extremity weakness, sensory changes, absent reflexes, single or multiple levels of neurological involvement. Babinski present.||*Comprehensive metabolic panel, ESR and CBC.MRI. Plain radiographs do not offer adequate sensitivity and specificity when index of suspicion for neoplasm is high.|
* See the following Discussion for elaboration
Step 2: Screen for a life-threatening condition (Discussion)