Leukemia is a cancer of the blood. The body makes far too many white blood cells, and they do not work as they should. Those extra cells crowd out the healthy ones, so a person may feel very tired and weak, bruise or bleed easily, catch infections, and — without treatment — the illness can kill.

Leukemia is a cancer of the bloodLeukemia（白血病）是一種血液的癌症。 The body makes far too many white blood cells身體會製造出太多的白血球， and they do not work as they should而且這些白血球沒辦法正常發揮功能。 Those extra cells crowd out the healthy ones這些多出來的細胞會把健康的細胞擠掉， so a person may feel very tired and weak所以一個人可能會覺得非常疲倦、虛弱， bruise or bleed easily容易瘀青或出血， catch infections容易感染， and — without treatment — the illness can kill而且如果不治療，這個病可能會致命。

There is not one single leukemia: doctors split it by how fast it grows (acute or chronic) and by which kind of white cell is involved. Treatment is much better than it once was, especially for some kinds in children, but it is still a serious disease.

There is not one single leukemia並不是只有一種 leukemia：doctors split it by how fast it grows (acute or chronic)醫生會依照它長得多快來分類（急性或慢性）， and by which kind of white cell is involved也依照牽涉到哪一種白血球來分類。 Treatment is much better than it once was治療方式已經比以前好很多了， especially for some kinds in children尤其是兒童的某些類型， but it is still a serious disease但這仍然是一種嚴重的疾病。

American English writes leukemia; British English usually writes leukaemia. In plain talk people also say blood cancer.

American English writes leukemia美式英語寫 leukemia；British English usually writes leukaemia英式英語通常寫 leukaemia。 In plain talk平常說話時 people also say blood cancer人們也會說 blood cancer（血癌）。