A "bad" white blood cell (WBC) level, medically known as leukopenia, is generally considered to be below 4,000 cells per microliter of blood. However, the precise definition varies slightly depending on the laboratory and the individual's age. Some sources define it as less than 3,500 cells/µL for adults and others use a threshold of less than 4,500 cells/µL. A very low neutrophil count (a type of WBC crucial for fighting infection), specifically fewer than 500 neutrophils per microliter, is considered severe neutropenia.
Understanding White Blood Cell Counts
White blood cells are a vital part of your immune system, fighting off infections and illnesses. A normal WBC count typically ranges from 4,500 to 11,000 cells per microliter (4.5 to 11.0 × 109/L), although this can vary slightly depending on the lab and individual factors. A low WBC count signifies that your body isn't producing enough of these infection-fighting cells, increasing your risk of infections.
Causes of Low WBC Counts
Several factors can contribute to a low WBC count, including:
- Viral or bacterial infections: Sometimes, a temporary drop in WBC count occurs during an infection as the body battles the invading pathogens.
- Autoimmune diseases: Conditions like lupus or rheumatoid arthritis can attack and damage white blood cells.
- Certain medications: Some drugs, such as chemotherapy, can suppress bone marrow function, leading to a decreased WBC production.
- Bone marrow disorders: Conditions affecting the bone marrow (where WBCs are produced) can significantly impact WBC levels.
- Genetic disorders: Rare genetic conditions can impair WBC production.
- Severe allergies: In cases of severe allergic reactions, certain types of WBCs like eosinophils or basophils may increase, causing a reduction in other WBC types.
Importance of Consulting a Doctor
A low WBC count is not something to ignore. If you experience symptoms like frequent infections, prolonged fatigue, or unexplained bruising or bleeding, it's crucial to consult a doctor. They can perform a complete blood count (CBC) to determine your WBC levels and investigate the underlying cause. Treatment will depend on the identified cause.
