What is anemia?

Is a decrease in normal number of red blood cells (RBCs) or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin deficiency. Since hemoglobin (found inside RBCs) normally carries oxygen from the lungs to the tissues, anemia leads to hypoxia (lack of oxygen) in organs. Since all human cells depend on oxygen for survival, varying degrees of anemia can have a wide range of clinical consequences. The three main classes of anemia include excessive blood loss (acutely such as a hemorrhage or chronically through low-volume loss), excessive blood cell destruction (hemolysis) or deficient red blood cell production (ineffective hematopoiesis). Anemia is the most common disorder of the blood. There are several kinds of anemia, produced by a variety of underlying causes.

Red blood cells are designed to carry oxygen to places all over the body where it's needed. You can think of them like a bread truck taking bread to everyone so they won't grow hungry. If the truck is the red blood cell, the bread in it is the oxygen. They pick up the bread at the bread distribution center (that's like the lungs) and take them to everyone's houses.

Now, you can't just pile the back of a truck full or bread--you need something to put it in. So each of the trucks have lots of bread crates, each one carrying a few loaves of bread. Hemoglobin is like these crates. Each red blood cell is full or hemoglobin molecules, and each hemoglobin molecule has 4 spots to carry oxygen. There are thousands of these hemoglobin molecules in every red blood cell, each able to carry 4 oxygen molecules. Empty trucks with empty crates come back to the distribution center and get all their crates filled with bread, just like red blood cells full of hemoglobin come to the lungs to get their hemoglobin filled with oxygen.

-> This brings us to anemia. Anemia is when there is a problem with this distribution system: something has gone wrong and there isn't enough oxygen getting to the cells. There are a few main ways this can happen:

First way--Not enough trucks (red blood cells) or crates (hemoglobin) being made: Red blood cells only last for about 3 months in the body, just like trucks eventually break down and won't run any more. So just like there are factories to make more trucks, there are factories in the body to make more red blood cells. These are in the bone marrow. If there is a problem with the factory then not enough red blood cells will get made. Some drugs can cause this and so can some kinds of cancer. The hemoglobin only lasts so long too, so just like the crates will wear out and need replaced, hemoglobin needs to be replaced. There could the a problem with hemoglobin being made in the body. The body needs iron as one of the parts used to make hemoglobin, so if someone is low in iron, there won't be hemoglobin and so it's as though there aren't enough crates to carry the bread.

Second way--Too many trucks (red blood cells) are being destroyed: Sometimes red blood cells are made badly, and it's like the factory sends out a recall notice and all the trucks go to the junk yard to get crushed. There are cells called macrophages that live in the spleen actually swallow the red blood cells and digest them to recycle their parts. But if too much of this happens there won't be enough red blood cells to carry around oxygen. This can happen if the red blood cells have a strange shape.

Third way--trucks (red blood cells) are all driving off the road into ditches (bleeding out of the vessels). If someone is bleeding, especially if its a little bit of bleeding that happens for a long time, eventually the bone marrow factory won't be able to keep up and there won't be enough red blood cells. This can happen if someone is bleeding into their intestines and this blood leaves their body through defecation, or if someone is bleeding into their abdominal space. Either way they are losing blood, and may not even notice it. Women can have especially heavy menstrual periods which can also cause this.

There are other things that can go wrong with the body's oxygen carrying system: parts used to make red blood cells or hemoglobin missing (like folate deficiency); machinery used to make red blood cells or hemoglobin missing (like vitamin B12 deficiency); machinery used to make red blood cells or hemoglobin making their products badly (like thalasemia or alcoholism); red blood cells getting attacked by the immune system (like aplastic anemia); the message not getting to the factory that more red blood cells are needed (this message is called erythropoietin and it comes from the kidneys so in kidney failure it can be low causing the bone marrow factories to not be in production); and red blood cells being attacked and destroyed by bacteria (like in malaria).


[Symptoms]
When people aren't getting enough food, they go hungry, and that's what happens in anemia. The cells go hungry, and so they can't operate as well is normal. This causes the person with anemia to feel tired and week. Their fingers and toes, and later their whole hands and feet will be cold. The red lining of the mouth and eyelids loses color and they become more pale because there are fewer red blood cells under the skin. They may feel dizzy and may have a hard time concentrating. Their heart beat will often be more fast than normal. If the cause of their anemia is not enough iron, the anemia can cause spoon shaped finger and toe nails. If their red blood cells are getting destroyed, they may have jaundice (their skin turns yellowish).


[Treatment]
Fixing the problem may be as simple as getting what is missing (for example, taking vitamin B12 in vitamin B12 deficiency) or it may be very difficult. (If the bone marrow factory has the wrong instruction set and is making the hemoglobin wrong, the person may need regular transfusions to give them blood made by someone else.)