Written by Dr. D. Rao


  1. A condition in which there is interference in the uptake or release of Oxygen thereby leading to failure to eliminate Carbon dioxide. Many rapid death of Medico-legal importance are fundamentally due to an interference with oxygenation of the times. For practical purpose such death may be classified by the manner in which the hypoxia (O2 deficiency) or the anoxia (total lack of oxygen) is initialed.
  2. Death due to interference with oxygenation as a result of hypoxia or anoxia..

Hypoxic death can be initiated by hypoxic, anoxic, stagnant or histotoxia.

Anoxic death can be initiated by anoxic anoxia or histotoxic anoxia.

The terms hypoxia and anoxia are often used synonymously.

General pathological changes-
  1. Capillaries are particularly susceptible to hypoxia and anoxia, and hypoxic or anoxic injury of the capillaries will  result in their dilation. This is followed by stagnation of blood in the dilated capillaries and in the venules, which accounts for the capillovenous engorgement which is a major feature of the general pathological findings in rapid hypoxic and   anoxic death.
  2. Injury to the capillary wall is often accompanied by petechial hemorrhage in the tissues.
  3. ­ Capillary permeability oedema.
  4. Cyanosis
  5. Post mortem fluidity of blood
  6. Cardiac dilatation

Asphyxia is classified into different types

  1. Mechanical asphyxia.
  2. Chemical Asphyxia.
  3. Environmental asphyxia.
  4. Pathological asphyxia.
  5. Miscellaneous.

Mechanical Interference with Respiration.


  • a. Hanging(Suspension)
  • Ligature Strangulation
  • Manual Strangulation
  • Smothering
  • Gagging
  • Choking
  • Drowning

Asphyxia Images