Any circumstances that prevents breathing by obstruction of the nose and mouth causes

Smothering It may be brought about by any circumstances that prevents breathing by obstruction of nose and mouth. Smothering agent is usuaklu fabric, pillow, or hands. Some times sand, grain, mud, flour, thick grass or vegetation may be responsible for blocking air passages. Death in such cases occur either by the occluding substance pressing over the nose and mouth or by the passive weight of the head pressing the nose and mouth into the occlusion. Ref: TEXTBOOK OF FORENSIC MEDICINE AND TOXICOLOGY KRISHNAN VIJ FIFTH EDITION PAGE 115