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Current time:0:00Total duration:7:39

Video transcript

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 mess you can point to it and say that's a source of our problem we need to get rid of it right away either with surgery or with medicine and 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 to cancer of the blood specifically to cancer of blood cells so what are these cells these blood cells that I'm talking about well let's draw a blood vessel which is where all of the blood is contained and when most people think of blood they they think of a liquid so that's what I'm 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 and hopefully you can see that which are really important for carrying oxygen and oxygen is required by all of the organs in our blood everything from your brain to your muscles require oxygen and then there are these cells that are called platelets which actually aren't cells at all they're little chunks or fragments of cells that form blood clots to help stop bleeding and 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're called blood cells but they're actually not made in the blood they're made inside the bone so I'm going to draw a bone and if you were to look at the boy 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'd see something like this you'd see that on the outside of the bone is this hard part that we all know about but that UT 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 this red spongy tissue and 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 so that we can see what bone marrow looks like 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 white blood cell starts multiplying really rapidly and out of control and it starts over taking the bone marrow kind of 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 clot 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 and secondly it's 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 and 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 symptoms okay so firstly we said we see a decrease the number of red blood cells right which I'm just going to abbreviate as RBC's for red blood cells and 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 patients start to experience some shortness of breath and because red blood cells give the blood it's 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 bruising easy bruising okay and finally we said that there's fewer white blood cells which I'm just going to abbreviate as WBC's right and since white blood cells help fight off infection this leads to more frequent infections increased number of infections or increased susceptibility to infections and 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 weight loss significant weight loss which are things that you've seen in lots of other cancers because you also have rapidly dividing cells and other cancers and then finally the leukemia cells start to grow into the wall of the bone and if you've ever broken if you've 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 a doctor will often start off by getting a blood test if they get a blood test the first thing that you'll see is is this picture over here you'll see fewer of the healthy 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 looking inside by actually looking inside the bone marrow and so 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 needle a long needle inside the bone and drawing out some fluid and then looking at that stuff under the microscope and and that's actually called a bone marrow bone marrow aspiration so in a nutshell this is what leukemia is all about