2.2 Present Illness (HPI)

Present Illness (HPI)

Quick Answer: The history of present illness expands the chief complaint into a full clinical narrative using structured mnemonics — OPQRST and OLDCARTS — to capture onset, quality, radiation, severity, and modifying factors. For neuromusculoskeletal complaints, mechanism of injury and aggravating/relieving positions are the details most likely to separate discogenic, facet-mediated, and radicular pain patterns on NBCE Part III.

From Chief Complaint to a Full Narrative

The chief complaint tells you what the patient came in for; the present illness tells you everything else about that complaint — how it started, what makes it better or worse, whether it has happened before, and where it travels. A well-built HPI should let a colleague who never met the patient predict, with reasonable confidence, what the exam will show before they lay a hand on the patient.

Two structured mnemonics dominate chiropractic and general clinical history-taking. Both cover the same clinical ground; the difference is emphasis and ordering.

OPQRST and OLDCARTS Compared

Either mnemonic, used completely, satisfies the documentation standard tested on Part III. What examiners look for is completeness and internal consistency — an HPI that reports "pain is worse with forward bending" but omits any aggravating/relieving section elsewhere is an incomplete history, even if OPQRST letters were nominally addressed.

Mechanism of Injury

Mechanism of injury (MOI) describes the specific movement or force that produced the complaint, and it is one of the highest-yield details in a neuromusculoskeletal history because it narrows the anatomic hypothesis before any orthopedic testing occurs.

• Flexion-loaded MOI (lifting with a rounded back, bending and twisting) — associated with disc-related pathology; annular loading is highest in flexion combined with rotation.
• Extension-loaded MOI (overhead reaching, arching backward, a fall onto the back) — associated with facet joint irritation and, in older patients, spondylolisthesis or pars stress.
• Axial/compressive MOI (a fall onto the buttocks, a jump landing) — raises concern for vertebral compression, especially with osteoporosis risk factors.
• Rotational/torsional MOI (twisting while the feet are planted) — associated with combined disc and facet strain.
• High-velocity MOI (motor-vehicle collision, sports collision, fall from height) — regardless of the pain pattern reported, mandates a lower threshold for imaging and neurologic screening.
• Insidious/no clear MOI — gradual onset with no identifiable trigger shifts the differential toward degenerative, inflammatory, or non-mechanical causes and should prompt a more thorough review of systems.

Aggravating and Relieving Factors

Positional response is one of the most clinically useful — and most heavily tested — pieces of the HPI, because different pain generators respond in opposite directions to the same movement.

The Valsalva response deserves special attention on Part III: pain that clearly worsens with coughing, sneezing, or straining at stool is a classic sign of increased intradiscal or intrathecal pressure and points toward a disc-related or space-occupying process rather than a pure facet or myofascial source.

Prior Episodes

A history of prior, similar episodes changes both prognosis and clinical suspicion:

• Recurrent episodes with full resolution between them support a mechanical, recurrent-strain pattern and generally carry a more favorable prognosis for conservative care.
• Progressively worsening episodes, or episodes that resolve less completely each time, suggest a degenerative process and should prompt closer monitoring.
• Response to prior treatment (chiropractic, physical therapy, injections, surgery) is directly predictive of response to a similar approach this time and should always be documented.
• A first-ever episode in an older patient with no trauma carries a different risk profile than a tenth episode of the same low back pain in a 30-year-old and should raise the index of suspicion for non-mechanical causes.

Radiation and Paresthesia Patterns

Distinguishing where pain and numbness travel — and whether that pattern is neurologic or non-neurologic — is central to differentiating radicular pain from referred pain.

Paresthesia that follows a clean dermatomal map (for example, lateral calf and dorsum of the foot for an L5 pattern) is far more specific for nerve root involvement than vague, non-dermatomal numbness, which is more often referred or non-organic in origin.

Quick Recap

• OPQRST and OLDCARTS cover the same ground; completeness matters more than which mnemonic is used.
• Mechanism of injury — flexion, extension, axial, rotational, high-velocity, or insidious — narrows the anatomic hypothesis before the exam.
• Discogenic pain classically worsens with sitting, flexion, and Valsalva; facet pain classically worsens with extension and standing/walking.
• Prior episodes and their response to treatment shape both prognosis and the current differential.
• True radicular patterns follow a dermatome and correlate with nerve tension signs; referred pain is broader, deeper, and rarely crosses the knee.