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What is leukemia?

Leukemia is a collection of cancers which create a large amount of immature blood cells. These immature blood cells take up space in the bone marrow, preventing the bone marrow from making healthy blood cells such as platelets, red blood cells, and white blood cells. Learn about the symptoms of this disease which include prolonged bleeding, frequent infections, and bone pain. Created by Nauroz Syed.

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  • aqualine ultimate style avatar for user alinalevakova
    How does the blood cells that are created in the bone marrow get out into our bodies? Do our bones have holes?
    (33 votes)
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    • leaf green style avatar for user Joanne
      Actually our bones have a large number of arteries and veins supplying the bone cells with oxygen ,nutrients and picking up carbon dioxide, wastes and blood cells. Our bones are dynamic changing tissues, they are not blocks of cement although it is easy to think otherwise. The new blood cells that were made in the bone marrow go into the sinusoidal capillaries in the bone marrow that have openings large enough to allow red blood cells, white blood cells and platelets to enter the blood vessels and get into the body's circulation.
      (30 votes)
  • duskpin ultimate style avatar for user Shani Karjalainen
    is it hard to become an leukemia doctor?
    (4 votes)
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  • orange juice squid orange style avatar for user rick lee
    Is leukemia a cancer of the blood marrow or the total blood makeup? I guess, I am asking if leukemia is more than just cancer of the blood marrow
    (8 votes)
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  • spunky sam blue style avatar for user Prometheanacademy
    At she mentions that the bone is filled with red spongy tissue - bone marrow. If you look at the diagram the hard shell is only about 30-40% of the thickness of the bone.

    If the hard shell on the outside is not that thick, then how come bones don't break more often? For example, I can fall on the floor from my chair without breaking my arm.

    Is the diagram not to scale?
    (7 votes)
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    • leaf blue style avatar for user dysmnemonic
      It depends on what bone it is (and where along that bone), but the diagram is basically right. While the outside layers of cortical bone are really strong, they're also quite heavy. If the entire bone was made up of it, then it'd be much more brittle and much heavier. Having the spongy bone on the inside helps to reduce the weight, helps to make the bone a bit more flexible, and helps to distribute forces on the bone across more of the hard outside. All of this makes the bone stronger and helps to reduce the stress on the major weight-bearing bones.
      (5 votes)
  • piceratops ultimate style avatar for user Nivedita
    Why is it that a patient having leukemia experiences bone pain in all the bones throughout the body, even though the leukemia cell production had started in only one bone?
    (6 votes)
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  • starky ultimate style avatar for user 😎InkyBlossom#TeamPhoniex (Inactive)
    Is there a cure for Leukemia? I mean, that seems scary!!
    (4 votes)
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    • duskpin ultimate style avatar for user nithyagottipati
      Though as of right now there is no actual "cure" for Leukemia, there are many different types of treatment options and studies ongoing to better the percentage of patients recovering from the disease. Depending on certain features and details about the patient (including age and initial white blood cell count), a doctor will decide which type of treatment to use on him or her. These treatment options can include:
      -Chemotherapy, one of the main treatments used for children with Leukemia, though drug combinations and dosages will definitely differ. Chemo can be given by mouth, into a vein, or into the fluid as well. Intensive Chemotherapy can be given to a patient when needed, but it has a wide range of side effects which will have to be monitored and treated afterwards.
      -Radiation Therapy, which basically has high energy rays attempt to kill the cancer cells formed in the bone marrow. This can also be used in a small dosage before stem cell transplants take place.
      -Stem Cell Transplants, which introduces new, healthy blood-forming cells into the body
      -Targeted Therapy, where specific drugs are used to identify and attack cancer cells without harming the normal cells
      As you said, leukemia is a scary disease, but we are taking small, yet sure steps in preventing it as much as we can. Through donations, research, and the support of others, patients with leukemia have a better chance of recovering, and I seriously hope they do.
      (3 votes)
  • purple pi purple style avatar for user alinalee378
    Does this disease affect your daily life? Please vote up if u have the same question!
    (4 votes)
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    • aqualine ultimate style avatar for user Sterre
      It will definitely affect your daily life greatly. Unlike some other cancers, leukemia affects the entire body. It makes the patient very weak and tired and a lot more susceptible to infections or other diseases. Easy bleeding and bruising is also common and continuous fever and general pain (in bones and joints) can be expected. If leukemia isn't treated it will in all likeliness be fatal, and leukemia patients often stay in hospitals for a long long time while they are being treated.
      (3 votes)
  • starky ultimate style avatar for user bkelley
    I thought Leukemia was when the platelets in your blood could not function correctly making a cut deadly.
    (1 vote)
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  • old spice man green style avatar for user Kellian Jacob Sisovic
    Can you get leukemia at any age?
    (1 vote)
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  • leafers sapling style avatar for user Meghana
    Can you possibly use a replacement of bone marrow to solve this problem?
    (2 votes)
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Video transcript

Voiceover: When most people hear the word cancer, they usually think of a tumor, so they think of a group of cells that are dividing really rapidly that eventually form a mass. And you can see that mass. You can point to it and say, "That's the source of our problem. "We need to get rid of it right away, "either with surgery or with medicine." I think what makes leukemia harder to understand and harder to visualize than other types of cancers is the fact that with leukemia you don't necessarily see a tumor, and that's because leukemia is a cancer of the blood. Specifically, it's a cancer of blood cells. So, what are these blood cells that I'm talking about? Well, let's draw a blood vessel, which is where all of the blood is contained. When most people think of blood, they think of a liquid, so that's what I am shading in, the liquid part of the blood. But blood has lots of cells in it too. So, for one, it has these cells called red blood cells, and hopefully you can see that, which are really important for carrying oxygen and oxygen is required by all of the organs in our body, everything from your brain to your muscles requires oxygen. Then there are these cells that are called platelets, which actually aren't cells at all. They are little chunks or fragments of cells that form blood clots to help stop bleeding. Then you have these guys. There are several different types of white blood cells, which is what our body uses to fight off infection. So, these are the guys that protect us from bacteria and viruses and parasites. So, these cells are found in the blood. That's why they are called blood cells. But they are actually not made in the blood. They are made inside the bone. So, I'm going to draw a bone. If you were to look inside the bone, so if you were to take a slice of bone like this and you were to look at it, so this is your eye right here looking inside the bone, you would see something like this. You would see that on the outside of the bone is this hard part that we all know about, but you would see that bone isn't solid all throughout. There's actually this hollow cavity in the center of the bone, and that hollow cavity is filled with his red, spongy tissue. That red, spongy tissue is called bone marrow, and bone marrow is where all of these different blood cells are made. So, I'm going to clear that out so that we can see what bone marrow looks like and what's going on inside bone marrow. If you looked inside, you'd see red blood cells being made, you'd see some cells making platelets, and you'd see white blood cells being made, right? And this is normal. This is all completely normal. But in leukemia, one of these cells, it could be a red blood cell, a platelet, or a white blood cell, starts multiplying really rapidly and out of control and it starts overtaking the bone marrow, kind of like this. And that's a problem for two reasons. Firstly, this cell that's dividing really rapidly, this leukemia cell, doesn't serve any function like a normal blood cell does. So, it doesn't carry oxygen. It doesn't fight off infection or help make blood clots. It kind of does nothing. It's kind of a waste of space, and that's a problem because we don't want to use any of our body's energy making cells that don't help the body, right? Secondly, it is a problem because if any one cell starts dividing really rapidly and taking up a lot of space inside the bone marrow, that leaves behind very little space and very little food for the other cells to grow. So, because of this, the bone marrow isn't able to make as many of those other normal, healthy blood cells. And if it can't make them, then it can't supply them into the blood, and that's the problem you see with leukemia, where you start seeing fewer red blood cells in the blood, that's those guys, and fewer platelets and fewer white blood cells in the blood. Then, eventually, when the leukemia cells run out of space to grow inside the bone marrow, they leak into the blood. So, you start to see leukemia cells in the blood, kind of like that, and actually this picture right here explains almost all of the symptoms that you see in leukemia. So, let's make some room to talk about the symptoms of leukemia. Okay, so firstly we said we see a decrease in the number of red blood cells, right, which I'm just going to abbreviate it as RBCs for red blood cells. Since red blood cells carry oxygen, this leads to symptoms like weakness and tiredness and fatigue, and the fatigue is from the brain not getting enough oxygen. And the body compensates for this by starting to breathe more quickly. So, the patient starts to experience some shortness of breath. And because red blood cells give the blood its red color, the patient starts looking paler when they have fewer red blood cells. We also said that we see a decrease in the number of platelets in leukemia. So, if the patient starts bleeding for whatever reason, they don't have enough platelets around to form that blood clot that stops the bleeding. So, they experience prolonged bleeding and they also see easy bruising. Okay. And finally, we said that there is fewer white blood cells, which I'm just going to abbreviate as WBCs, right. And since white blood cells help fight off infection, this leads to more frequent infections, an increased number of infections, or increased susceptibility to infections. These cells, these leukemia cells, that are really rapidly dividing, take up a lot of the body's energy. And because of that, you see symptoms such as weakness and symptoms such as significant weight loss, which are things that you see in lots of other cancers because you also have rapidly dividing cells in other cancers. And then, finally, the leukemia cells start to grow into the wall of the bone, and if you have ever had a bone fracture or bone infection, you know that the wall of the bone has lots of very sensitive sensory nerves in it, and because of that, the patients with leukemia start experiencing bone pain, and that's not pain in just one bone, it's pain throughout the bones of the body. So, it's more generalized bone pain. So, if a patient starts showing signs and symptoms of leukemia, a doctor will often start off by getting a blood test, and if they get a blood test, the first thing that you will see is this picture over here. You'll see fewer of the healhy, normal cells and you may even see the leukemia cells in the blood, right? So, that would lead to the suspicion that maybe the patient has leukemia, and that suspicion can be confirmed by actually looking inside the bone marrow, and that's this. I'm just drawing in the cavity inside the bone. And you can look inside the bone marrow by actually sticking a long needle inside the bone and drawing out some fluid and then looking at the stuff under the microscope, and that's actually called a bone marrow aspiration. So, in a nutshell, this is what leukemia is all about.