Hypoxia (synonym: lack of oxygen, oxygen starvation) - low content of oxygen in the tissues. The lack of oxygen in the tissues is called anoxia.
Insufficient supply of oxygen to tissues may be in violation: 1) external respiration (lack of oxygen in the air, diseases of the respiratory system) - hypoxic hypoxia; 2) transport of oxygen (cardiovascular diseases, bleeding, blood diseases) - gipotermicescoe hypoxia; 3) tissue respiration (some metabolic diseases, poisoning toxins that inhibit tissue respiration) - gistologicescoe hypoxia.
During hypoxia occurs a number of compensatory reactions directed on increase of oxygen consumption. These include reflex strengthening of breath (dyspnea), tachycardia, increased cardiac output, increase the speed of blood flow, the increase in the number of red blood cells by entering them from the depot and the increase of hemoglobin in blood, activation of biochemical processes, providing tissue respiration. With the further development of hypoxia, when the adaptive mechanisms are not capable to ensure a normal consumption of oxygen, there is the development of symptoms of oxygen starvation. At the forefront are the phenomena of oppression of the Central nervous system: fatigue, drowsiness, heaviness in the head, then the disturbance of sensation, movement disorders and loss of orientation. In severe hypoxia occurs loss of awareness, involuntary urination, defecation, periodic breathing, decrease heart rate, low blood pressure, followed by respiratory arrest and death.
For the prevention and treatment of hypoxia, in addition to addressing its causes, conduct oxygen therapy (see), and to breathe the oxygen for excitation of the respiratory center add 5-7% CO2.