When a tissue enters anoxia, cells cannot obtain energy or perform their functions.
Oxygen is the essential molecule for life as we know it. All the cells in our body use it as ‘fuel’ for energy and to fulfill all its functions. Therefore, anoxia is harmful to the tissues and might lead to a heart attack.
The word anoxia comes from Greek and means a lack of oxygen. It is a term used to refer to the lack of oxygen in a specific tissue or organ. It is incompatible with life, since, as we said, cells cannot survive without oxygen.
Another similar term is hypoxia, which is the decrease in oxygen supply to a tissue. Unlike anoxia, when the word hypoxia used, it means that even though it has decreased, there is still some oxygen. In this editorial, we describe what takes place when these circumstances occur.
What Happens in a Hypoxia or Anoxia Situation?
When we breathe, gas exchange takes place in our lungs, through which we expel carbon dioxide and introduce oxygen into our body. This oxygen binds to hemoglobin in red blood cells.
Thanks to the circulatory system, blood reaches all the tissues of our body. Thus, cells capture oxygen and can obtain energy to perform their essential functions. The truth is that each tissue has different oxygen needs.
For example, nervous tissue, such as the brain, has very high oxygen requirements. Merely being in anoxia for a few minutes already causes significant damage to it. However, other more resistant tissues are less affected by the lack of oxygen.
What consequences does it have?
The damage caused by the anoxia situation will depend on many factors first, as we have mentioned, of the oxygen requirement of each tissue. It also influences the time that passes from the anoxia until oxygen arrives again.
Other important factors are age and the presence of other diseases. The important thing is to know that, in maintained anoxia conditions, all the tissues of our body suffer.
What Types of Anoxia are there?
There are different types of, depending on the mechanism that produces this lack of oxygen:
- First, we found anoxic anoxia. What happens is that there is not enough oxygen in the air breathed. For example, it is very typical in high altitude places.
- Anoxic anoxia may also include choking. The idea is that not enough oxygen captured, either because it is not in the right concentration or because it does not reach the lungs.
- On the other hand, there is an anemic anoxia. In this case, the blood cannot transport oxygen because the hemoglobin altered or because there is not enough of it. We must remember that there are also many types of anemia and circumstances that can cause it.
- Ischemic anoxia is the blood flow interrupted, and the blood cannot reach the tissue, either due to an obstruction of the vessel or due to bleeding. In this group, we find pathologies such as strokes or cardiac arrest.
- Finally, we find toxic anoxia. It is the one that occurs, for example, in poisoning by carbon monoxide or alcohol. The toxin in question interferes with the use of oxygen.
Although it can happen in any tissue, we must bear in mind that the most sensitive organ to this lack of oxygen in the brain. For this cause, the maximum of the time we talk about hypoxia or cerebral anoxia.
When this occurs, holding it for several minutes can already lead to irreversible injury—for example, cerebral palsy or cognitive problems. We must know that anoxia is a medical emergency and that we have to act quickly.