You can google hereditary spherocytosis and get accurate documents, especially from reputable websites like webmd. Here is my interpretation and experience with it.
First of all, it is a genetic disorder. I was born with it, and I have family members on my mother's side with it. As far as I know my two siblings do not present with symptoms. According to the hematologist, my children each have a 50% chance of having it. Obviously he has not read my blog post on statistics! Too bad I wasn't on my game, or maybe I would have told him about it.
So what happens is my bone marrow produces some red blood cells that are abnormal, called spherocytes. They are spherical in shape instead of flat and round. Their cell walls are missing an important protein. They don't expand at all (the hematologist said that to test for it years ago they would put cells into sucrose water and they would explode), and don't hold as much oxygen. When they pass through the spleen they are prematurely destroyed because of the fragility of the cell wall. In people with a mild form of the disorder, the bone marrow simply remakes more blood cells to compensate. It is possible to live for years without knowing or having symptoms of the disorder, then something (such as a virus) will trigger an aplastic crisis (anemia, low blood counts) and the bone marrow suddenly cannot keep up. The spleen swells, and the "cure" is to remove the spleen (splenectomy). This does not stop the bone marrow from making abnormal blood cells. It does allow the blood cells to have a normal life span, therefore it cures the anemia (and also eliminates the risk of a ruptured spleen and the crisis that involves).
Iron deficient anemia is a little different. Probably what I have experienced most of my adult life is just that. It is normal to be anemic during the third trimester of pregnancy, when the baby really starts building its iron stores. The doctor mentioned I had been as low as 8.8. I don't actually remember that. I do remember getting down into the 9's. I am usually never in the 12's when I am tested (because why would I be tested during any NORMAL time). Always being on an iron supplement gets me back on track right away. In this instance, I have been taking iron supplements as soon as I found out. I'm also not pregnant and can't explain why I would have low iron. The hematologist said that my iron stores look good, and I'm not taking it for granted (I'll take whatever precious little information he is willing to give). As a child I was always borderline anemic my mom says. I remember trying to down liquid iron mixed in orange juice (yuck) and also eating fried chicken livers (not so bad with mustard) my grandmother made. My spleen was palpable as a child (the doctor could feel it), but it wasn't as I grew and it wasn't during my recent previous pregnancies, according to my doctor. It is definitely palpable now. I can feel it, Mitch felt it, and Kristin felt it. :)
I talked with my regular family doctor today, who helped answer a few remaining questions I have. She supported the hematologist's decision to remove my spleen, saying that the best evidence was the fact that my numbers went so low and remained low with just a virus. I should have a pneumococcal vaccine before the surgery and possibly the influenza vaccines as well. She also said I could ask if the surgeon would like to "take care of" my gallbladder at the same time...he may not, but it wouldn't hurt to ask. :) I'm just thinking...there are now gall stones sitting there...and in a possible future pregnancy they could be a problem. If not in a future pregnancy, just life in general. That's all I know until after Wednesday!