 Moving on, while we're talking about different iron studies, let's go ahead and discuss what values you will see with these iron studies and different types of diseases. Oftentimes, you'll see this on the USMLE and they will give you the results of studies and ask you what is this disease? So if you can have a very strong idea of what each disease shows on the iron studies, you can answer questions very easily with this. So first we'll start out with iron deficiency. The serum iron in iron deficiency is obviously going to be decreased. It's in the name. There's a deficiency of iron. The total iron binding capacity or the transferrin, which is what transfers or transports the iron in the blood, will be up because there's lower iron. There's more capacity to bind the iron. Ferritin, which is the storage medium for iron in the body, will be down because there's less iron in the body. And then when you do a ratio of serum iron to total iron binding capacity, you will see that is greatly decreased because of the increase in the total iron binding capacity that is over the serum iron. For chronic disease, you're going to see the serum iron decreased. The total iron binding capacity is decreased. The ferritin or the storage in the body will be increased. The body is trying to store more ironing for the use in that chronic disease. And your serum iron and your serum iron over total iron binding capacity ratio will be decreased as well. With hemochromatosis, you will see an increase in serum iron. So this is a holding on of the iron in the body. Sometimes this can be due to pathologies. Other times it can be due to blood transfusions. You're loading a lot of iron into the body in a blood transfusion. So someone that has often blood transfusions, they can get hemochromatosis here. So you're getting an increase in the serum iron. Your total iron binding capacity will be going down because this increase in the serum iron is going to decrease the transfer transferrinin in the body. Ferritin, which is a storage medium for iron in the body, will increase because it has to store more. There's more in the body. It's got to be stored. And then your serum iron and total iron binding capacity ratio will obviously be greatly increased as the serum iron increases there. For pregnancy or oral contraceptive use, the oral contraceptive pill often mimics a pregnancy in the body. That is what decreases the release of eggs during the monthly cycle. So there's no change in the serum iron and there's no change in the ferritin. There's no difference in the storage. There's no difference in the amount that's in the blood. But there will be an increase in the total iron binding capacity. And there will be a decrease in the serum iron total iron binding capacity ratio. Thank you for watching.