Death from Asphyxia Notes Forensic Medicine

Introduction 

Asphyxia is a life-threatening condition caused by a severe lack of oxygen to the body, leading to tissue damage, unconsciousness, and death if not treated immediately. It is caused by interference with breathing—such as choking, drowning, strangulation, or suffocation—resulting in decreased oxygen and increased carbon dioxide in the blood. Every type of asphyxial death in forensic is discussed below


DEATH FROM ASPHYXIA – HANGING

Definition

Hanging is a form of asphyxial death caused by suspension of the body by a ligature around the neck, the constricting force being the weight of the body.

TYPES OF HANGING

1. Based on Body Position

  • Complete hangingEntire body is suspended.
  • Partial hangingPart of the body touches the ground (kneeling, sitting, lying, etc.).➝ Most suicidal cases are actually partial.

2. Based on Knot Position

  • Typical hanging – Knot at occiput (back of neck).
  • Atypical hanging – Knot at side, front, or any other part of the neck.

3. Based on Manner of Death

  • Suicidal – Most common.
  • Homicidal – Rare, usually associated with signs of struggle.
  • Accidental – Rare (e.g., children, auto-erotic).

MECHANISM OF DEATH IN HANGING

Death occurs due to multiple factors:

  1. Asphyxia – Compression of airway.
  2. Venous congestion – Jugular vein compression → cerebral hypoxia.
  3. Vagal inhibition – Pressure on carotid sinus → cardiac arrest.
  4. Fracture of cervical vertebrae – Rare, common only in judicial hanging (fracture of C2–C3 = Hangman’s fracture).

ANTEMORTEM SIGNS OF HANGING

  • Struggle marks (in suicidal incomplete hangings rarely)
  • Cyanosis
  • Petechial hemorrhages
  • Congestion of face

POSTMORTEM FINDINGS IN HANGING

A. External Findings

1. Ligature Mark

  • Oblique, non-continuous, above the level of thyroid cartilage.
  • Pale, parchment-like, dry.
  • More prominent on the opposite side of the knot.
  • In typical hanging, mark runs upward and backward to the occiput.

2. Saliva Dribbling

  • Running down from the mouth, usually on one side.
  • Considered a strongest sign of antemortem hanging.

3. Face Findings

  • May be pale or congested.
  • Petechial hemorrhages may or may not be present.
  • Tongue protrusion is variable.

4. Other External Signs

  • Stretched, elongated neck (rare).
  • Abrasions or bruises around neck (if struggle or movement).
  • Dribbling of urine or feces in some cases.

POSTMORTEM FINDINGS IN HANGING

A. External Findings

1. Ligature Mark

  • Oblique, non-continuous, above the level of thyroid cartilage.
  • Pale, parchment-like, dry.
  • More prominent on the opposite side of the knot.
  • In typical hanging, mark runs upward and backward to the occiput.

2. Saliva Dribbling

  • Running down from the mouth, usually on one side.
  • Considered a strongest sign of antemortem hanging.

3. Face Findings

  • May be pale or congested.
  • Petechial hemorrhages may or may not be present.
  • Tongue protrusion is variable.

4. Other External Signs

  • Stretched, elongated neck (rare).
  • Abrasions or bruises around neck (if struggle or movement).
  • Dribbling of urine or feces in some cases.

POSTMORTEM FINDINGS IN HANGING

A. External Findings

1. Ligature Mark

  • Oblique, non-continuous, above the level of thyroid cartilage.
  • Pale, parchment-like, dry.
  • More prominent on the opposite side of the knot.
  • In typical hanging, mark runs upward and backward to the occiput.

2. Saliva Dribbling

  • Running down from the mouth, usually on one side.
  • Considered a strongest sign of antemortem hanging.

3. Face Findings

  • May be pale or congested.
  • Petechial hemorrhages may or may not be present.
  • Tongue protrusion is variable.

4. Other External Signs

  • Stretched, elongated neck (rare).
  • Abrasions or bruises around neck (if struggle or movement).
  • Dribbling of urine or feces in some cases.

MEDICO-LEGAL ASPECTS

  • Hanging is usually suicidal.
  • Assess for any signs of struggle, intoxication, or homicide.
  • Ligature must be preserved for laboratory and pattern comparison.
  • Inquest must consider scene examination.

DEATH FROM ASPHYXIA – STRANGULATION

Definition

Strangulation is a form of asphyxial death caused by constriction of the neck by a ligature, hands, or any other object, without suspension of the body.


TYPES OF STRANGULATION

1. Ligature Strangulation

Neck compressed by rope, wire, cloth, dupatta, etc.

2. Manual Strangulation (Throttling)

Neck compressed by hands, thumb, fingers, or forearm.

3. Mugging / Garroting

Neck compressed by hook, stick, or knee applied from behind.

4. Bansdola / Spanish Windlass

Twisting a stick inserted in ligature to increase pressure.

MECHANISM OF DEATH

Death occurs mainly due to:

1. Asphyxia

Compression of airway → obstruction.

2. Venous Congestion

Compression of jugular veins → cerebral hypoxia.

3. Carotid Artery Pressure

Stops blood flow to brain → rapid unconsciousness.

4. Vagal Inhibition

Pressure on carotid sinus → sudden cardiac arrest (seen in manual strangulation).

ANTEMORTEM SIGNS

  • Signs of struggle and resistance common.
  • Nail marks, scratches, abrasions.
  • Cyanosis, petechiae.
  • Frothy discharge in some cases.

POSTMORTEM FINDINGS IN STRANGULATION

A. External Findings

1. Ligature Mark (in ligature strangulation)

  • Horizontal, transverse, completely encircles the neck.
  • Located low on the neck, usually below the thyroid cartilage.
  • Not oblique, unlike hanging.
  • Abraded, reddish, may show patterned imprint of ligature.

2. Injuries on Neck (Manual Strangulation)

  • Finger marks, abrasions.
  • Nail scratches (crescentic).
  • Bruises around mouth, jaw, and chin.

3. Face

  • Congested, cyanosed.
  • Marked petechial hemorrhages in eyelids, conjunctiva.
  • Swollen lips and protruded tongue.

4. Signs of Struggle

  • Multiple abrasions, bruises on body.
  • Defence wounds on hands and forearms.

B. Internal Findings

1. Neck Structures

  • Extensive hemorrhage in neck muscles.
  • Fracture of hyoid bone (common).
  • Fracture of thyroid cartilage.
  • Rupture or tearing of strap muscles → confirms antemortem violence.

2. Airway

  • Congested mucosa.
  • Blood-stained froth in trachea.

3. Lungs

  • Heavy, congested, oedematous.
  • Tardieu’s spots present.

4. Brain

  • Marked congestion and edema.

DIFFERENTIATING STRANGULATION FROM HANGING

Feature

Hanging

Strangulation

Ligature mark

Oblique, above thyroid cartilage

Horizontal, below thyroid cartilage

Body weight

Acts as force

No body weight; external force used

Fracture of hyoid

Rare (except elderly)

Common

Internal neck injuries

Minimal

Severe, extensive

Dribbling of saliva

Common

Rare

Face

Pale or congested

Cyanosed, congested

Common manner

Suicidal

Homicidal


MEDICO-LEGAL ASPECTS

  • Strangulation is almost always homicidal.
  • accidental and suicidal cases are extremely rare.
  • Presence of struggle marks, defensive injuries, multiple bruises strongly support homicide.
  • Ligature must be preserved for pattern comparison.
  • Thorough scene investigation required.

DEATH FROM ASPHYXIA – DROWNING

Definition : Drowning is a form of asphyxial death caused by submersion of the mouth and nose into water, leading to inability to breathe, hypoxia, and death.

TYPES OF DROWNING

1. Wet Drowning

Water enters lungs → most common (80–90%).

2. Dry Drowning

Due to laryngospasm → little or no water enters lungs.

3. Secondary Drowning

Death occurs hours after rescue due to pulmonary oedema.

4. Immersion Syndrome (Hydrocution)

Sudden cardiac arrest due to vagal inhibition when a person jumps into cold water.

5. Near Drowning

Survival after submersion (may later die due to complications).

MECHANISM OF DEATH

  • Asphyxia (major mechanism)
  • Cardiac arrhythmias due to dilution of electrolytes
  • Vagal inhibition (particularly in cold water)
  • Pulmonary oedema

ANTEMORTEM SIGNS

  • Struggle marks (scratches from aquatic plants)
  • Water swallowing
  • Presence of foreign material in airways (sand, weeds)
  • Cyanosis

POSTMORTEM FINDINGS IN DROWNING

A. External Findings

1. Wet Clothes, Mud, Weeds

Indicates death in water or postmortem immersion.

2. Cutis Anserina (Goose Skin)

Due to contraction of tiny muscles around hair follicles.

3. Washerwoman’s Hands and Feet

Wrinkling, sodden, bleached skin due to water absorption (appears after 30 min – 1 hr).

4. Froth at Mouth and Nostrils

  • Fine, white, persistent froth → characteristic sign.
  • If wiped off, it reappears.

5. Skin Abrasions

Caused by contact with rocks, plants, animals (postmortem or antemortem).

6. Eyes

  • Open or closed
  • Conjunctiva congested
  • Sometimes fine petechiae

B. Internal Findings

1. Lungs

  • Voluminous, ballooned, emphysematous, overlapping the heart (ballooned lungs).
  • Waterlogged, heavy, edematous.
  • Presence of frothy fluid on sectioning.
  • Subpleural petechiae known as Paltauf’s Hemorrhages.

2. Stomach

  • Water in stomach (as a result of swallowing).
  • May contain sand, weeds, mud.
  • Water may also be found in small intestines.

3. Air Passages

  • Froth and water in trachea and bronchi.
  • Presence of foreign matter (sand/algae).

4. Middle Ear

  • Rupture of tympanic membrane in some cases (pressure).

5. Diatoms

  • Diatoms in bone marrow, brain, and organs support antemortem drowning.
  • Used mainly in freshwater drowning.

6. Blood

  • Hemodilution (in freshwater drowning).
  • Increased magnesium (in seawater drowning).

FRESHWATER VS SEA WATER DROWNING

Feature

Freshwater

Sea Water

Water movement

Hypotonic

Hypertonic

Blood effect

Hemodilution

Hemoconcentration

Lung appearance

Ballooned, overinflated

Heavy, stiff lungs

Mechanism

Ventricular fibrillation

Pulmonary edema

MEDICO-LEGAL ASPECTS

  • Most cases are accidental.
  • Suicidal drowning occurs, especially in females (jumping into wells/ponds).
  • Homicidal drowning is rare; usually in children, intoxicated, or unconscious individuals.
  • Important to investigate the scene, clothing, injuries, and toxicology.

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