Q2 LONG ANSWER 10M ★ High-yield

Describe hanging with its types, postmortem findings and medicolegal aspects.

Forensic Medicine · 2nd Professional — Para-Clinical

Definition and Types

Hanging is a form of asphyxial death in which the body is suspended by a ligature around the neck, and the constricting force is the weight of the body or of a part of it.

Classification	Types
By the position of the knot	Typical — the knot at the nape (occiput) and the pressure symmetrical, so both carotids and both vertebral arteries are occluded and the face is pale. Atypical — the knot anywhere else, most often at the side, so compression is asymmetrical and the face is congested and cyanosed with petechiae
By the degree of suspension	Complete — the body hangs clear of the ground. Partial (incomplete) — some part of the body touches the ground, the person kneeling, sitting, squatting or even lying. Partial hanging IS common and does not exclude hanging — which is the point most often misunderstood
By the manner	Suicidal — overwhelmingly the commonest; accidental — in children at play, in sexual asphyxia, and from a sari or scarf caught in machinery; homicidal — exceedingly rare and requires the victim to be first incapacitated; and judicial
Lynching	Hanging by a mob without trial

The pressures required are remarkably small, and this table is the reason partial hanging works: jugular veins occlude at about 2 kg; carotid arteries at about 5 kg; the trachea at about 15 kg; and the vertebral arteries at about 16.6 kg. The weight of the head alone (about 5 kg) is therefore sufficient to occlude the carotids, so a person can hang from a door handle while sitting on the floor
Mechanism of death — principally occlusion of the cerebral circulation, causing unconsciousness within 10 to 15 seconds and death in minutes; also asphyxia from airway obstruction; vagal inhibition from pressure on the carotid sinus, causing instantaneous death with a negative autopsy; and, in judicial hanging, fracture-dislocation of the cervical spine with transection of the cord

CLINICAL PEARL

The weight of the head alone will hang a person, which is why partial hanging is common and why suicide is not excluded by the feet touching the floor. Five kilograms occludes the carotids; a head weighs about that. People are found hanging while kneeling, sitting, squatting, even lying, and investigators regularly treat this as proof of homicide. It is not — and the doctor should say so, because the alternative reading sends investigations in entirely the wrong direction.

Postmortem Findings

Feature	Findings in hanging
The ligature mark	Oblique, running upward toward the knot; non-continuous, with a gap beneath the knot; situated high on the neck, above the thyroid cartilage, between the larynx and the chin; deepest opposite the knot. The base is pale, hard and parchment-like from drying, and may show the pattern of the ligature
Face	Pale in typical hanging; congested and cyanosed with petechiae in atypical hanging
Tongue	Protruded, swollen and dark where the ligature is above the larynx
Saliva	Dribbling from the angle of the mouth, running downward along the chin and chest according to the position of the head. This is a vital sign, requiring an active salivary secretion, and it is therefore very strong evidence of antemortem hanging — and it cannot be reproduced after death
Eyes	Petechiae in the conjunctivae and eyelids in atypical hanging; the eyes may be open or closed
Hands and genitals	The hands are clenched; postmortem lividity in the lower limbs and forearms ("glove and stocking" distribution) from the upright position; seminal emission, and involuntary passage of urine and faeces — none of which indicates a sexual element
Neck structures	Bruising of the strap muscles is uncommon; the hyoid bone is fractured in a minority, and then usually the greater cornu, more often in older people whose hyoid has ossified. The thyroid cartilage may be fractured
Vascular signs	Amussat'S sign — a transverse tear of the intima of the carotid artery, from sudden stretching, indicating that the suspension was violent and the person alive. SIMON'S sign — haemorrhage into the anterior aspect of the intervertebral discs of the lumbar spine, from stretching of the vertebral column

Amussat's and Simon's signs are genuinely useful because they are vital signs of suspension which cannot be produced by hanging a body after death; both should be looked for specifically
Cadaveric spasm may grip the ligature, and again cannot be simulated

Manner of Death

Suicide accounts for the overwhelming majority of hangings, and the supporting findings are: the ligature and its point of attachment accessible to the deceased; a means of reaching the point of suspension — a stool, bed or table — and its position; the doors secured from within; a suicide note; a psychiatric history or a precipitating event; the absence of defence injuries; and the absence of any other significant injury
Homicidal hanging is exceedingly rare, since a conscious adult cannot be hanged without a severe struggle; it requires the victim to be first drugged, intoxicated, or rendered unconscious, or to be a child or a frail person. It is suggested by defence injuries, other injuries, evidence of restraint, a ligature the person could not have obtained, and a point of suspension they could not have reached
The critical differential is a homicide followed by suspension, to simulate suicide — and this is far commoner than true homicidal hanging. It is detected by: a ligature mark of strangulation type beneath the hanging mark; absence of the vital signs, especially the dribbling of saliva, Amussat's and Simon's signs, and any vital reaction in the mark; postmortem lividity inconsistent with suspension; and other injuries
Accidental hanging — in children playing, in industrial accidents where clothing or hair is caught, and in autoerotic (sexual) asphyxia

Distinguishing Antemortem Hanging from Postmortem Suspension

Finding	Antemortem hanging	Body suspended after death
Vital reaction in the ligature mark	Present — congestion at the margins, ecchymosis in the deeper tissues, inflammatory change on histology	Absent — the mark is pale and yellow with clean tissue beneath
Saliva dribbling from the angle of the mouth	Present and running downward — requires an active salivary secretion and cannot be reproduced after death	Absent
Amussat’S sign	Transverse tear of the carotid intima — a vital sign of violent suspension	Absent
SIMON’S sign	Haemorrhage into the anterior lumbar intervertebral discs from stretching of the spine	Absent
Cadaveric spasm gripping the ligature	May be present; cannot be simulated	Absent
Postmortem lividity	In the lower limbs and forearms — a "glove and stocking" distribution consistent with suspension	Inconsistent with the position — commonly on the back, showing the body lay flat for hours first
A second mark	One mark only	A low transverse strangulation mark may lie beneath the high oblique hanging mark — the single most important finding to exclude
Other injuries and toxicology	Usually none	Defence injuries; or a sedative or alcohol level indicating prior incapacitation

Applied Aspects

Do not treat partial hanging as evidence of homicide; the weight of the head suffices, and people are found hanging while sitting or kneeling. This misunderstanding regularly misdirects investigations
Look for dribbling saliva and photograph it; it is one of the strongest vital signs available and is destroyed as soon as the body is cleaned or moved
Cut the ligature away from the knot and preserve the knot intact, rejoining the cut ends; the knot is evidence about who tied it
Look for a second mark beneath the hanging mark; a horizontal, continuous, low mark under an oblique high one indicates strangulation followed by suspension
Check that the lividity fits the suspension; lividity on the back in a body found hanging means it lay flat for hours before being suspended
Take toxicology always; homicidal hanging requires prior incapacitation, and a sedative or alcohol level is often the only way to demonstrate it
Amussat and Simon signs are vital signs of suspension and cannot be produced by hanging a body after death; both should be sought specifically
Five kilograms occludes the carotids — about the weight of a head — which is the whole reason partial hanging works
Typical hanging gives a pale face and atypical a congested one, because the symmetry of the pressure decides whether the arteries are occluded too
Seminal emission means nothing; it occurs in ordinary hanging and is not evidence of a sexual element
The hyoid is fractured in only a minority of hangings, and its integrity therefore excludes nothing
Cut the ligature away from the knot and rejoin the ends with thread; the knot may show handedness or occupation
Lividity in a glove and stocking distribution is consistent with suspension, and lividity on the back is not
Look for a second, lower, transverse mark in every hanging; it is the single most important thing to exclude
Dribbling saliva is destroyed by cleaning the body, so it must be looked for and photographed before anything else is done
Homicidal hanging is very rare; homicide followed by suspension is far commoner, and the two must not be confused
Vagal inhibition may kill instantly in hanging with a wholly negative autopsy, which explains some deaths with minimal findings
Lynching is hanging by a mob without trial, and is homicide however it is described locally

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