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Smoke Inhalation

Smoke Inhalation Overview

The number one cause of death related to fires is smoke inhalation. An estimated 50-80% of fire deaths are the result of smoke inhalation injuries rather than burns.

Smoke inhalation occurs when you breathe in the products of combustion during a fire. Combustion results from the rapid breakdown of a substance by heat (more commonly called burning). Smoke is a mixture of heated particles and gases. It is impossible to predict the exact composition of smoke produced by a fire. The products being burned, the temperature of the fire, and the amount of oxygen available to the fire all make a difference in the type of smoke produced.

Smoke Inhalation Causes

Smoke inhalation damages the body by simple asphyxiation (lack of oxygen), chemical irritation, chemical asphyxiation, or a combination of these.


  • Simple asphyxiants

    • Combustion can simply use up the oxygen near the fire and lead to your death when there is no oxygen for you to breathe.

    • Smoke itself can contain products that do not cause direct harm to you, but they take up the space that is needed for oxygen. Carbon dioxide acts in this way.

  • Irritant compounds

    • Combustion can result in the formation of chemicals that cause direct injury when they contact your skin and mucous membranes.

    • These substances disrupt the normal lining of the respiratory tract. This disruption can potentially cause swelling, airway collapse, and respiratory distress.

    • Examples of chemical irritants found in smoke include sulfur dioxide, ammonia, hydrogen chloride, and chlorine.

  • Chemical asphyxiants

    • A fire can produce compounds that do damage by interfering with your body’s oxygen use at a cellular level.

    • Carbon monoxide, hydrogen cyanide, and hydrogen sulfide are all examples of chemicals produced in fires that interfere with the use of oxygen by the cell during the production of energy.

    • If either the delivery of oxygen or the use of oxygen is inhibited, cells will die.

    • Carbon monoxide has been found to be the leading cause of death in smoke inhalation.

Smoke Inhalation Symptoms

Numerous signs and symptoms of smoke inhalation may develop. Symptoms may include cough, shortness of breath, hoarseness, headache, and acute mental status changes.

Signs such as soot in airway passages or skin color changes may be useful in determining the degree of your injury.

  • Cough

    • When the mucous membranes of your respiratory tract get irritated, they secrete more mucus.

    • Bronchospasm and increased mucus lead to reflex coughing.

    • The mucus may be either clear or black depending on the degree of burned particles deposited in your lungs and trachea.

  • Shortness of breath

    • This may be caused by direct injury to your respiratory tract leading to the decreased oxygen delivery to the blood, the decreased oxygen-carrying capacity of the blood itself because of chemicals in smoke, or the inability to use oxygen at the cellular level.

    • You may have rapid breathing as you attempt to compensate for these injuries.

  • Hoarseness or noisy breathing

    • This may be a sign that fluids are collecting in your upper airway and may cause a blockage.

    • Irritant chemicals may cause vocal cord spasm, swelling, and constriction of the upper airways.

  • Eyes: Your eyes may be red and irritated by the smoke, and you may have burns on the corneas in your eyes.

  • Skin color: Skin color may range from pale to bluish to cherry red.

  • Soot

    • Soot in the nostrils or throat may give a clue as to the degree of smoke inhalation.

    • Your nostrils and nasal passages may be swollen.

  • Headache

    • In all fires, people are exposed to various quantities of carbon monoxide.

    • You may have no respiratory problems, but carbon monoxide may still have been inhaled.

    • Headache, nausea, and vomiting are symptoms of carbon monoxide poisoning.

  • Changes in mental status

    • Chemical asphyxiants and low levels of oxygen can lead to mental status changes.

    • Confusion, fainting, seizures, and coma are all potential complications following smoke inhalation.

WebMD Medical Reference from eMedicineHealth

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