概述
White blood cells are an important part of your body’s immune system. They’re responsible for protecting your body against infections and invading organisms. You have five types of white blood cells:
- neutrophils
- lymphocytes
- monocytes
- 嗜酸性粒细胞
- basophils
Each of these can be affected in different ways if you have a particular condition or disease.
白细胞（WBC）计数测量血液中的白细胞数，WBC差异决定了血液中存在的每种类型的白细胞的百分比。差异也可以检测未成熟的白细胞和异常，这两者都是潜在问题的迹象。
A WBC count can also be called a leukocyte count, and a WBC differential can also be called a leukocyte differential count.
Your doctor may request a WBC count and differential if they suspect you have one of several conditions, including:
- anemia
- infection
- leukemia
Both tests can help your doctor determine if your symptoms are due to high or low WBC levels, which will help them understand what condition you may have. WBC counts can also be used to monitor certain disease processes and illnesses.
No special preparation is necessary for a WBC count or differential. Your doctor may ask you to stop taking certain medications, including over-the-counter supplements or vitamins, for several days before the sample collection occurs. Medicines, both prescription and over-the-counter, can affect white blood cell counts.
To conduct a WBC count and differential, your doctor will need to collect a blood sample from you. Blood is typically drawn from a vein in either the bend of your arm or in your hand. Once the blood is collected, it’s sent to a lab for analysis.
WBC count and differential tests have very few risks. Apart from bruising or soreness at the puncture site, this test shouldn’t cause any problems or complications. Some people may feel moderate pain and a stinging sensation during the blood draw, and some people may feel sick or lightheaded during or after the blood draw. If you do, let your doctor or nurse know and remain seated until the feeling has passed.
虽然罕见，有一些血液的人可以发展血肿 - 直接在皮肤下积累血液。有些人也可能在收集地点的皮肤中产生感染，但这也非常罕见。
根据您的医生订购的测试，您可能需要等待几天的结果。单一的WBC计数或差异测试并不讲述身体中发生的事情的整个故事。但是，这两个测试都是重要的工具，帮助您的医生找出可能导致您的症状。差分结果可以表示某些条件，下面讨论。
An increase in neutrophils in your blood may be caused by:
- 急性压力
- infection
- 痛风
- rheumatoid arthritis
- 甲状腺炎
- trauma
- pregnancy
A decrease in neutrophils in your blood may be caused by:
- anemia
- bacterial infection
- chemotherapy
- influenza or other viral illnesses
- 辐射暴露
您血液中淋巴细胞的增加可能是由：
- 慢性感染
- mononucleosis
- leukemia
- 病毒感染，如腮腺炎要么麻疹
A decrease in lymphocytes may be caused by:
- chemotherapy
- 艾滋病毒感染
- leukemia
- 败血症
- 辐射暴露，无论是偶然还是从放射治疗
An increase in monocytes may be caused by:
- 慢性炎症疾病
- tuberculosis
- viral infection, such as measles, mononucleosis, and mumps
单核细胞的减少可能是由以下方式引起的：
- bloodstream infection
- chemotherapy
- bone marrow disorder
- 皮肤感染
An increase in eosinophils may be caused by:
- an allergic reaction
- 寄生感染
嗜碱性粒细胞的降低可能是由急性过敏反应引起的。
Your doctor will go over the test results with you and, if need be, come up with a treatment plan suited specifically for you. You may need to have more tests performed to confirm a diagnosis, and you may need to get another WBC count and differential in the near future.