 breathing. For most of us it's an automatic body function that we take for granted. It is the process of taking in air to the lungs and exchanging gases with our environment. Carbon dioxide is a gas produced by all living cells in the body as a waste product. This gas has a very important role in maintaining chemical balance in the body and controlling breathing. Excess carbon dioxide is eliminated by the lungs during exhalation. However, some amount of this gas must remain in the body. The concentration of this gas in the body is monitored closely by the brain. The average adult breathing cycle is 12 to 16 breaths per minute. Breathing can be stimulated or slowed down through voluntary muscle control. When we are exposed to situations of emotional stress, fright or pain, our body usually reacts by breathing faster than normal. This reaction is known as hyperventilation. Hyperventilation is a condition where the rate and depth of breathing is abnormally increased. This causes an excessive loss of carbon dioxide from the body, creating a chemical imbalance in the blood. The brain defends itself against this and voluntary chemical imbalance by restricting its blood flow. This restriction of blood flow to the brain will cause individuals to experience symptoms such as poor judgment, impaired memory, performance impairment, delayed reaction time and muscle and coordination. And if the chemical imbalance is not reversed quickly enough, unconsciousness will occur. The main cause of hyperventilation in a pilot is an emotional reaction, meaning anxiety, fear, anger or stress. The key to preventing both hyperventilation and hypoxia, that is insufficient oxygen due to altitude exposure, is early recognition of signs and symptoms. Here are a few distinguishable differences between hyperventilation and hypoxia. The onset of symptoms from hyperventilation occurs slowly and gradually. Hypoxia symptoms depending on altitude are rapid. With hyperventilation, muscle activity can become spastic, especially in the upper extremities. Whereas with hypoxia, muscles may be soft and limp with little or no activity. Hyperventilation will cause the skin to appear pale and clammy. With hypoxia, a person's skin may appear blue or cyanotic. The difficulty in recognizing hyperventilation in flight is that the symptoms are similar to hypoxia. To help differentiate between hyperventilation and hypoxia, monitor these elements. Your flight altitude, your cabin altitude if pressurized, your oxygen system if one is being used, your emotional state, the awareness of your current flight environment. Pilots should recognize that hyperventilation and hypoxia can occur simultaneously, making it very difficult to diagnose the problem. This becomes readily apparent when we look at some of the symptoms that can occur with both conditions. Dizziness, lightheadedness, blurred vision, numbness, tingling and muscle incoordination. In aviation, any impaired performance is considered a serious safety risk. The most effective way to prevent hyperventilation is monitor your rate and depth of breathing. Learn to recognize stressors that would cause you to over breathe. If you suspect a problem with hyperventilation or hypoxia, use the following checklist which will correct both conditions. Don your oxygen mask. Check that the oxygen regulator is turned on, 100% oxygen is being delivered and that all connections are secure. Slow down your rate and depth of breathing. Descend to an altitude where hypoxia is unlikely to occur. Typically this means 10,000 feet or below if the safety of the flight is not endangered. If hyperventilation occurs during a flight below 10,000 feet, you should slow down your rate and depth of breathing until symptoms clear. Then resume breathing at a normal rate. Breathing can be slowed by breathing into a bag or talking aloud. Hyperventilation can easily occur to first time flyers, including passengers and students, but it can happen to any pilot. The key is to manage the circumstances and not let the cockpit management deteriorate. If you or someone in your aircraft is hyperventilating, be sure to treat the cause as well as the symptoms. Hyperventilation is a condition where the rate and depth of breathing are abnormally increased. Carbon dioxide is the primary gas that maintains the chemical balance in the blood and is monitored closely by the brain. The main cause of hyperventilation to an aircrew is emotion, meaning anxiety, fear, anger or stress. The most effective ways to prevent hyperventilation is to be sure to monitor your rate and depth of breathing. Recognize those stressors that would cause you to over breathe. If you suspect a problem with hyperventilation or hypoxia, use this checklist which will correct both conditions. Don your oxygen mask. Check that the oxygen regulator is turned on, 100% oxygen is being delivered and that all connections are secure. Slow down your rate and depth of breathing. Descend to an altitude where hypoxia is unlikely to occur. Typically this means 10,000 feet or below if the safety of the flight is not endangered. With regard to aviation, if any of your performance abilities become impaired, you are putting yourself and others in the flying environment at risk. Be able to differentiate between hyperventilation and hypoxia. It's your responsibility as a pilot to treat the cause as well as the symptoms.