What Does It Mean To have Low White Blood Cells?

Our body produces white blood cells, or leukocytes, which help fight bacterial, viral, and fungal infections, Mayo Clinic explains on its website.

Leukocytes are part of the immune system. They are a type of blood cell produced in the bone marrow and found in the blood and lymphatic tissue, according to the MedlinePlus website.

The five main types of white blood cells, according to the Merck MSD Manual, are:

Basophils

Eosinophils

Lymphocytes

Monocytes

Neutrophils

When we get sick, white blood cells travel through the bloodstream and tissues to where they are needed to help the body fight infections and diseases.

What happens when you have low white blood cells?

Leukopenia is a low blood cell count. This means you have too few white blood cells circulating in your blood. A long-term low count increases your risk of infections and other diseases, according to the Mayo Clinic.

Some diseases, such as cancer and HIV, a viral disease that attacks white blood cells, can cause this white blood cell count to drop. Likewise, certain medications, such as chemotherapy, reduce the number of white blood cells.

And what happens when the white blood cell count is high?

Leukocytosis, or high white blood cell count, indicates that there are too many white blood cells circulating in the blood, due to an infection, explains Mayo Clinic.

When we get sick, the body produces more white blood cells to fight bacteria or viruses and other foreign substances that may be causing the infection, MedlinePlus describes.

What is the normal number of white blood cells we should have?

In a given volume of blood, the number of white blood cells is expressed in terms of cells per microliter of blood. The total number is usually between 4,000 and 11,000.

Normally, people produce about 10 billion white blood cells a day, explains MSD.

When there are less than four thousand cells per microliter of blood, it is called leukopenia. When there is leukocytosis, there are more than 11 thousand cells per microliter of blood, it is called MSD.