Leukocytes: What Are They & What Causes Them to Be High or Low

Leukocytes, commonly known as white blood cells, are a type of of blood cell that is responsible for defending the body against infections and allergies, being an important part of the immune system.

These cells are transported in the blood and whenever a virus, bacteria, or any other type of organism comes into contact with the human body, they become active and try to eliminate it, in order to stop it from causing serious health problems.  

The normal amount of leukocytes in the blood is around 4.500 to 11.000 leukocytes per mm³ of blood in adults, however, this amount can be altered in some situations such as history of recent infection, excess stress, or immune diseases, like AIDS.

Leukocytes: What Are They & What Causes Them to Be High or Low

1. High white blood cell count

High white blood cell count (also known as leukocytosis) happens when there is more than 11.000 leukocytes per mm³ of blood.

  • Possible causes: infection or recent disease, excess stress, side effects of medication, allergies, rheumatoid arthritis, myelofibrosis or leukemia;
  • Symptoms: these are rare, but they may include fever over 100.4º F (38ºC), dizziness, difficulty breathing, tingling in the arms or legs and loss of appetite;

When this happens is important to visit a G.P. in order to diagnose a cause and start specific treatment if needed. This may include the use of antibiotics or corticosteroids, for example.

2. Low white blood cell count

A low concentration of leukocytes (also known as leukopenia) occurs when there is less than 4.500 leukocytes per mm³ of blood.

  • Possible causes: anemia, use of antibiotics or diuretics, bad nutrition, weakned immune system caused by HIV, leukemia, lupus or chemotherapy;
  • Symptoms: fatigue, recurrent infections, constant low fever, headaches and abdominal pain;

If this happens, it is recommended to visit a G.P. to diagnose the cause. However, in some cases it is also normal for some people to present low leukocytes without an actual cause.

Leukocytes in urine: what do they mean?

It is normal to present some leukocytes in urine as these are usually eliminated through the urine when they die. However, if you have an urinary tract infection or a serious disease, such as cancer, the amounts of leukocytes in the urine tend increase greatly.

Usually, high leukocytes in urine generate symptoms, such as foamy urine, fever, chills and can be related to the presence of blood in the urine. In these cases you must visit a G.P. or a nephrologist to diagnose the cause and start adequate treatment.

In addition, high leukocytes in the urine can also be a sign of pregnancy, especially when accompanied by an increase in the number of proteins in the urine. In these cases, you will need to do a pregnancy test or go to a gynecologist to avoid false diagnosis.

Learn more about the possible causes of leukocytes in urine and what to do.

Was this information helpful?
More on this subject: