Strangulation Assessment and Documentation

Clinical and forensic assessment of manual, ligature, and positional strangulation: signs and symptoms, the diagnostic challenge of absent external marks, documentation tools, and lethality risk.

Last updated: 19 Jun 2026

Strangulation is assessed through a combination of mechanism history, symptom inquiry, and systematic physical examination of the neck, face, and eyes. Between 50% and 70% of strangulation survivors present with no visible external neck injury, making direct questioning and documentation of symptoms such as loss of consciousness, voice change, and dysphagia as important as the physical findings. Internal injuries including carotid artery dissection and laryngeal oedema can cause death hours to days after an assault that initially appears survivable. Structured documentation tools, particularly the Strangulation Documentation Form developed by the Training Institute on Strangulation Prevention, consistently capture higher rates of clinically and forensically significant findings than unstructured narrative notes.

Strangulation is one of the most dangerous forms of physical assault and one of the most under-documented, because the external evidence is frequently absent. A perpetrator needs to apply only 4 pounds of pressure to compress the jugular veins and begin impeding blood flow to the brain, while the carotid arteries require around 11 pounds. At pressures readily achievable by one hand, a victim loses consciousness within seconds. At those pressures, the neck skin may show nothing at all.

Research on strangulation survivors has documented this clearly: somewhere between 50% and 70% of people who report being strangled have no visible external neck injury at presentation. A clinician who does not ask about strangulation specifically, or who treats an unremarkable neck examination as sufficient, will miss the diagnosis. Strangulation has to be a question on every intimate-partner violence and physical assault history.

This topic covers the three types of strangulation, the range of internal and external signs, the clinical findings that do show up when the neck is examined carefully (petechiae, conjunctival haemorrhage, voice changes, neurological symptoms), the structured documentation tools, and the critical lethality and delayed-death questions that must be part of every assessment and discharge plan.

By the end of this topic you will be able to:

Distinguish manual, ligature, and positional strangulation by mechanism, external mark pattern, and typical forensic context.
Identify the external and internal signs of strangulation, including petechiae, conjunctival haemorrhage, voice changes, and neurological symptoms, and explain why their absence does not exclude the diagnosis.
Describe the four delayed-death mechanisms after strangulation and apply the associated clinical warning signs to discharge and admission decisions.
Use a structured documentation approach (covering history, symptoms at the time of assault, current symptoms, physical findings by zone, and lethality indicators) to produce a forensically complete strangulation record.
Apply lethality risk criteria to determine when a strangulation patient requires admission or extended observation rather than discharge.

Key terms

Manual strangulation: Compression of the neck by one or both hands. The most common type in intimate-partner violence. Creates asymmetric, fingertip-sized contusions and may leave no marks at all.
Ligature strangulation: Compression by a cord, belt, wire, or similar item looped around the neck. The ligature mark shows the width and pattern of the material and runs roughly horizontally (unlike a hanging furrow, which angles upward).
Positional (postural) strangulation: Compression of the neck caused by the weight of the body or an external object constraining the airway or neck vessels without direct gripping. Seen in restraint deaths and some vehicular fatalities.
Petechiae: Pinpoint haemorrhages above the level of venous compression. They develop when venous outflow is blocked while arterial inflow continues, raising capillary pressure to rupture. Petechiae on the conjunctiva and facial skin support a strangulation mechanism.
Carotid artery dissection: A tear in the inner wall of the carotid artery caused by stretching or compression during strangulation. Can produce stroke hours to days after the strangulation event, contributing to delayed death or disability.
Strangulation Documentation Form: A structured clinical tool, developed originally by the Training Institute on Strangulation Prevention, that systematically prompts recording of mechanism, symptoms, and physical findings. Its use increases finding detection rates compared to ad-hoc documentation.

Types of strangulation

Three mechanisms produce strangulation injuries in clinical forensic practice, each with a characteristic physical pattern and forensic context.

Type	Mechanism	External marks	Forensic context
Manual	Hands, fingers, or forearm compress neck	Fingertip contusions (often absent or delayed), nail abrasions, grab marks on neck	Most common in IPV; asymmetric marks may indicate dominant hand; front-of-neck compression typical
Ligature	Cord, belt, wire, or similar item encircles neck	Horizontal patterned ligature mark (width mirrors material); petechiae above; abrasion at corners of mark	Homicidal, suicidal, or accidental context; mark runs horizontal, distinguishing from suicidal hanging (angled)
Positional	Body weight or constraint restricts airway/vessels without direct grip	May be no mark; pattern depends on constraint surface	Restraint deaths, prone restraint, vehicular; requires scene context for interpretation

External signs: neck marks, petechiae, and conjunctival findings

External examination of the strangulation patient includes the neck, face, and eyes. The neck may be unremarkable. The face and eyes are more informative, because petechiae, scleral haemorrhage, and periorbital oedema all develop above the level of compression even when the neck shows nothing.

External signs of strangulation: petechiae distribution and mark patterns.

Conjunctival petechiae: pinpoint haemorrhages on the inner surface of the eyelids (palpebral conjunctiva). Evert the eyelids to examine. High specificity for raised venous pressure.
Scleral haemorrhage: visible red patches on the white of the eye. Larger than petechiae; can be dramatic. Less specific than conjunctival petechiae but supports the same mechanism.
Facial petechiae: pinpoint haemorrhages on the face, forehead, and behind the ears. Examine under good lighting. A headlamp or colposcope increases detection.
Neck marks: when present, document precise location using clock-face notation around the neck, size, shape (fingertip oval, linear cord pattern), and colour. Photograph with a scale. Note that marks may develop or become more visible over 24-72 hours after the event.
Facial oedema and subconjunctival oedema: swelling of the face and eyelids may follow severe strangulation. Document and monitor; progression of oedema may indicate internal neck injury.

Internal and neurological signs

Strangulation can injure internal structures without producing visible external marks: the larynx, hyoid bone, trachea, carotid and vertebral arteries, and the brain. Symptoms that emerge during the assault or in the hours after it are the primary window into these internal injuries.

Loss of consciousness: reported by approximately 50% of strangulation survivors in some studies. Even brief loss of consciousness indicates global cerebral hypoxia and is a major risk indicator for neurological sequelae and delayed death. Always document.
Voice changes (dysphonia): hoarseness, altered pitch, or voice loss. May indicate laryngeal trauma, oedema, or haematoma. Persisting or worsening dysphonia is an indication for urgent otolaryngology review.
Dysphagia: difficulty or pain on swallowing. Indicates possible laryngeal, epiglottic, or hypopharyngeal injury. A patient with new dysphagia after strangulation should not be discharged without airway assessment.
Neurological symptoms: headache, visual disturbance, unilateral weakness, or facial droop after strangulation may indicate carotid artery dissection or cerebral hypoxic injury. These symptoms can be delayed.
Urinary incontinence during assault: involuntary voiding during strangulation indicates loss of voluntary sphincter control, implying prolonged or severe cerebral hypoxia. High-risk indicator.
Neck pain and tenderness: even without visible bruising, deep palpation of the neck may elicit tenderness over the larynx, hyoid, or cervical spine. Palpate gently and systematically.

Delayed death: mechanism and risk

Delayed death after strangulation is a forensically critical phenomenon. A victim who appears to recover, walks away, or is discharged from emergency care can die subsequently through mechanisms that were set in motion during the assault but manifest only hours or days later.

Mechanism	Pathophysiology	Clinical warning signs
Carotid artery dissection	Stretch or compression tears the tunica intima; thrombus forms and embolises to cerebral vessels	New-onset stroke symptoms: hemiplegia, aphasia, facial droop, hours to days post-event
Laryngeal/epiglottic oedema	Mucosal oedema progresses over hours, narrowing the airway progressively	Progressive stridor, worsening dysphagia, increasing voice change; can cause fatal airway obstruction
Hypoxic brain injury	Sustained hypoxia during unconsciousness causes neuronal death; full extent may not be apparent immediately	Cognitive changes, seizures, persistent headache, deteriorating consciousness
Vertebral artery dissection	Rotational or hyperextension component injures the vertebral artery	Cerebellar and posterior circulation stroke symptoms; ataxia, vertigo, diplopia

Four delayed-death mechanisms after strangulation: carotid dissection causes stroke via thrombus; laryngeal oedema narrows the airway over hours; hypoxic brain injury from unconsciousness produces neurological decline; vertebral artery dissection triggers posterior-circulation stroke. Each can cause death or disability hours to days after an assault that appeared survivable.

The Strangulation Documentation Form and structured assessment

Unstructured clinical notes on strangulation consistently miss key findings. Studies comparing ad-hoc narrative documentation to structured form documentation find that forms capture higher rates of symptoms, more complete physical findings, and better lethality risk information. The Training Institute on Strangulation Prevention has published a widely used Strangulation Documentation Form (SDF) used in many forensic nursing programmes.

History section: method of strangulation (patient's description); duration; whether pressure was continuous or intermittent; whether the patient lost consciousness; whether there was urinary or faecal incontinence.
Symptoms at time of assault: vision changes (blackening, seeing stars), hearing changes, difficulty breathing, difficulty swallowing.
Current symptoms at examination: neck pain, headache, voice change, dysphagia, neurological symptoms.
Physical findings section: TEARS across neck (by zone: anterior, lateral, posterior), face, and periorbital region. Petechial distribution by site.
Lethality indicators: loss of consciousness, incontinence, weapon present, threats to kill, escalating pattern.

Even when a formal SDF is not used, every strangulation examination should systematically work through these domains. Documentation limited to 'no marks on neck' is both clinically and forensically inadequate.

Worked example

Strangulation assessment in an intimate-partner violence presentation

Systematic documentation across a largely negative external examination.

A 31-year-old woman presents to the emergency department eight hours after an argument with her partner. She reports being grabbed around the neck with both hands for an estimated 30 seconds. She briefly 'blacked out' and then woke on the floor. She has a sore throat and some hoarseness. She declined to call police at home.

History (SDF): Manual strangulation, bilateral hands, approximately 30 seconds, loss of consciousness confirmed (woke on floor), no incontinence reported, current hoarseness and sore throat. Assault occurred 8 hours prior to examination.
Neck examination: anterior neck -- two small oval contusions, each approximately 1 x 0.8 cm, located 3 cm lateral to the midline at the level of the thyroid cartilage bilaterally. Colour: dark red-purple (consistent with recent). Right lateral neck -- no marks. Posterior neck -- no marks. Total TEARS neck: Ecchymosis (2 marks, locations as above), no other categories positive.
Eye and face examination: left palpebral conjunctiva -- 4-5 petechiae visible on eversion. Right conjunctiva -- 2 petechiae. Facial skin: no petechiae detected. Sclera: no haemorrhage. Documented and photographed.
Clinical assessment: voice is hoarse. Laryngoscopy requested. Otolaryngology review arranged. Patient counselled on delayed-death risks: given written information on returning immediately for any neurological symptoms, worsening hoarseness, or difficulty swallowing. Admission considered; patient declined; return-precautions documented. Safety planning initiated; advocate contact offered.

The record is complete: it captures the symptom history (loss of consciousness, hoarseness), the physical findings (bilateral neck ecchymosis, bilateral conjunctival petechiae), the clinical risk-management steps taken, and the patient's discharge decision with risk documentation. A narrative note saying 'strangled, no serious injuries found' would be none of these things.

Check your understanding

Question 1 of 4· 0 answered

Most strangulation survivors presenting to a forensic nurse have:

Key Takeaways

The majority of strangulation survivors have no visible neck injury; absence of neck marks does not exclude strangulation, and the examination must include eyes, face, and symptom history.
Petechiae in the palpebral conjunctiva, scleral haemorrhage, and facial petechiae develop from raised venous back-pressure above the compression level and may be the only external evidence of strangulation.
Loss of consciousness and urinary incontinence during strangulation are high-risk indicators for neurological injury and delayed death; any patient reporting these requires urgent assessment and admission consideration.
Delayed death after strangulation occurs via carotid dissection, progressive laryngeal oedema, hypoxic brain injury, and vertebral artery dissection; patients discharged must receive explicit return-precaution instructions covering these mechanisms.
Structured documentation tools, such as the Strangulation Documentation Form, consistently improve detection rates compared to unstructured narrative notes and should be used in every strangulation examination.

Does absence of neck bruising mean strangulation did not occur?

No. Research shows that most strangulation survivors have no visible external neck injury. The absence of marks does not rule out strangulation; it reflects the low pressure required to compress neck vessels and how quickly bruises may form (or not form) in the days after an event. Internal injury can be severe even when the neck looks unmarked.

What are petechiae and why do they matter in strangulation?

Petechiae are pinpoint haemorrhages caused by raised venous pressure when neck veins are compressed but neck arteries remain partially open. They appear as small red dots above the level of compression, on the conjunctiva, sclera, facial skin, and behind the ears. Their presence supports strangulation as a mechanism even when no neck marks are visible.

What is delayed death after strangulation?

Strangulation can cause death hours to days after the physical event appears to have ended, through mechanisms including carotid artery dissection, thromboembolism, hypoxic brain injury, or laryngeal oedema that progresses over hours. Any patient who loses consciousness during strangulation is at risk of delayed death and requires urgent medical evaluation and admission consideration.

What information should a strangulation documentation form capture?

A structured strangulation form captures: method (manual, ligature, positional), symptoms at the time of assault (loss of consciousness, vision change, urinary incontinence), symptoms at examination (dysphagia, voice change, neck pain, headache), physical findings using TEARS across the neck and periorbital region, and petechial distribution. The form prompts questions the examiner might otherwise miss.

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