Many of the common symptoms associated with brain injury (anxiousness, headaches, poor concentration) are the direct results from, or they are compounded and made worse because of, an inadequate delivery of blood and oxygen to the brain. Concussions and other forms of minor or traumatic brain injuries commonly damage the autonomic nervous system (ANS) which is responsible for regulating the supply of oxygen and other nutrients to the brain.
Our oxygen delivery system is a perfectly timed machine because we only have a 1-second reserve of oxygen in our brain tissue. Our primitive survival mechanisms are activated if our brain’s oxygen supply declines below normal because our brain perceives we are in danger, almost like we are drowning.
If the availability and delivery of oxygen for the brain drops below normal, a person cannot think as quickly or clearly and they are often inexplicably fatigued, anxious, and fidgety. They may also feel unusually thirsty or hungry with particular cravings for salt and sugar.
In response to the low oxygen levels, the body releases stress hormones that forces blood vessels to constrict, increasing blood and oxygen delivery to the brain. These hormones may also cause the individual to feel anxiousness or irritable, and the hormones can even cause panic attacks. In spite of these irritating side effects, the release of the hormones is necessary for the delivery of life-sustaining oxygen.
The primitive brain may also increase the movement of muscles because muscle contractions drive blood and oxygen to the brain as well. In some people this muscular response is so strong that sitting still for them is nearly impossible. The individual’s leg will bounce incessantly, they will tap their feet, or they will feel compelled to get up and move around. These types of movement and behavior can become so intense that some of these people are labeled as hyperactive.
The primitive brain in other individuals with brain damage will experience increased hunger for liquids and foods containing salt or sugar, they will crave the nicotine found in tobacco, or they will use prescriptions stimulants like ADD medication. This is because these substances and products also can boost the delivery of blood and oxygen to the brain.
The need for our primitive brain to maintain that oxygen supple for survival is so intense in some individuals that they feel they have developed addictions that defy willpower or logic. Some of these people can not quit drinking a particular brand of soda or eating and particular food. If these cravings are left unchecked over time, these people can develop obesity and disease such as diabetes, high blood pressure, and sleep apnea.
People can also develop addictions to the blood pressure boosting effects of nicotine. Nicotine triggers the nervous system receptors that affects blood vessel constriction, which temporarily results in improved brain blood flow and oxygen delivery. The smoker lights a cigarette, inhales nicotine that enters the bloodstream which then stimulates the idle nicotinic receptor, thereby boosting blood pressure and oxygen delivery to the brain. By chewing or smoking tobacco, an individual is able to bypass the damage to the autonomic nervous system and normalize brain oxygen delivery.
But the oxygen delivery boost from nicotine is short and it quickly fades. For the people whose primitive brains have discovered this nicotine boost, their brain commands them to continue to chew or smoke tobacco in spite of understanding the health risks and in spite of pressure to quit from their managers, coaches, friends, and family. And if that person does not understand they have an oxygen delivery problem they may mistakenly blame their inability to quit on themselves. But their problem has nothing to do from lack of education or a lack of strength, the problem is that their primitive survival mechanism is so powerful that it forces them to act because it fears they face the risk of death from that inadequate 1-second reserve of oxygen.
To better understand the brain blood pressure problem and the pull of gravity, consider the average one pack-a-day smoker. This person will want or need to smoke a cigarette every 30-60 minutes all day long but yet they are able to lay flat and sleep for 8 hours without smoking at all. If the person was truly addicted to nicotine, how can they sleep all of those hours in a row without getting up for a cigarette? The answer is that the real issue is gravity not the nicotine.
Once the smoker lays down flat in bed, they have removed the gravitation effects against the blood flow upwards towards their brains. In spite of brain damage, the smoker is able to get an adequate oxygen to their brain when laying horizontal and they no longer require the boosting effects of nicotine. But once they wake up in the morning and they try to get up and around, gravity once again works against their damaged system and the nicotine cycle starts over again and again.
When the brain damage is reversed in someone addicted to tobacco, they often report they start simply forgetting to smoke or buy cigarettes for days or for weeks at a time.
We have all been educated that tobacco and nicotine are bad for our health, but even more dangerous are the potential addictions and long term effects from illegal and prescriptions stimulants. Drugs such as cocaine, meth, Adderall, and Ritalin all stimulate the nervous system and also boost pressure and oxygen delivery to the brain.
Unless the underlying neurological damage is repaired, the primitive survival mechanisms will continue to use whatever combined methods it needs to drive blood and oxygen to the brain and survive.