Low white blood cell count is a condition where the numbers of the white blood cells in your body become too low. White blood cells (also called leukocytes) are part of the immune system, and they are the cells that protect your body against infections by bacteria, viruses, fungi, and parasites. Low white blood cell count is also known as leukopenia.
White blood cells are very important for health. Life is impossible without them. The microorganisms that cause diseases are literally everywhere, but most people do not get sick because they have ample numbers of white blood cells providing protection. Low white blood cell count often means there is a problem in the body, so it is not considered normal.
There are several kinds of white blood cells. Each has their own specialized purposes and different life spans. There are monocytes (morphs into other white blood cells), lymphocytes (releases antibodies, regulates immunity, and kills infected human cells), basophils (initiates inflammatory reactions), eosinophils (kills parasites and triggers allergic reactions), and neutrophils (main killers of bacteria and fungi).
Our body produces millions of different white blood cells continuously that replace worn out or dead ones. That is why their numbers remain relatively stable most of the time. The immune system is skillful in regulating the numbers of activity of white blood cells, increasing or decreasing numbers of a particular type as needed in the situation. Even in moments where we put ourselves at risk, like consuming dirty or spoiled food, inhaling dust laden with microorganisms, staying in crowded places, or being in places like airplanes, gyms, or hospitals, we often do not get sick because we have a good supply of white blood cells that kill pathogens before they cause infection.
If we do get sick, the immune system will initiate a series of actions to stop the growth of, or kill, the invading pathogens, as well as destroy infected or dying cells in the body. Infection often prompts a drastic rise in white blood cell counts. Doctors can easily know if you have an infection if they see that your white blood cell counts are higher than normal. The increased white blood cells give the body higher chances of stopping the infection.
Of course, there are cases where the white blood cell count falls. In most cases, it requires thorough investigation because it is often associated with health problems, some of which are serious. Low white blood cell count is not a diagnosis or a health condition. It is just a finding after a routine blood test.
Definition of low white blood cell count
The correct term for a blood test or exam is called complete blood count or CBC. Doctors often order a CBC because it analyzes the numbers of cell components, including white blood cells. The normal threshold for white blood cell count may differ. Mayo Clinic states that the normal range is 3.5 billion to 10.5 billion cells per liter of blood. Meanwhile, MEDLINE Plus states that the normal 4,500 to 11,000 white blood cells per microliter (mcL).
A CBC is the only way to determine the numbers of white blood cells in the body. Your doctor may order several CBC tests to monitor your blood cell counts.
The main purpose of white blood cells is protecting the body against infection by microorganisms. If their numbers become too low, you may become vulnerable to infections. Most people actually don’t feel any symptoms unless their white blood cell counts become very low.
If you have low white blood cell count for some time, you might have increased frequency of sickness or infections than usual.
Symptoms of infection include:
Having fever with temperature of 100.4° F (38° C) or higher
All microorganisms, except HIV, are not able to attack white blood cells head-to-head. Meanwhile, killing microorganisms are the main purpose of white blood cells. The body also naturally produces more white blood cells in case of infection or inflammation. That explains why infections cause increased numbers of white blood cells.
As we have mentioned before, our body makes white blood cells continuously. White blood cells are produced in the bone marrow, just like other components of the blood. Having low blood cell counts means there is something wrong in the production of white blood cells.
In most cases, low white blood cell count is a consequence of a disease. Some treatments can also cause it as a side effect. Malnutrition and nutrient deficiencies can also cause white blood cell counts to fall.
3 Top reasons for low white blood cell count
Low white blood cell count is often associated with diseases. Among the most common causes is a serious infection, which may use up white blood cells faster than they can be produced. Severe infection may develop if the disease is left untreated, or is not responding to treatment. It often happens in babies, very young children, or the elderly.
Low white blood cell count is often a feature of immunodeficiency or a compromised immune system. As you learned in school, white blood cells are the workhorse of the immune system. Low counts of specific white blood cells in the CBC can often reveal the cause of the immunodeficiency. Some of the most common conditions that cause immunodeficiency include systemic lupus erythrematosis (lupus), tuberculosis, dengue fever virus infection, rickettsia, psittacosis, Sjogren’s syndrome, Lyme disease, and Hodgkin’s lymphoma.
HIV infection is also a common cause of low white blood cell count. The human immunodeficiency virus mainly targets the CD T4 helper cells, the exact ones that trigger the immune system to act against infection. HIV causes white blood cell numbers to fail over time. Once the numbers of white blood cells become too low, opportunistic bacteria and viruses will invade the body and cause infection, resulting in a multitude of serious health problems that define AIDS. Having a diagnosed or undiagnosed HIV infection is a very common cause of low white blood cell count in both developed and developing countries.
A condition called sarcoidosis can also cause numbers of white blood cells to fail. Sarcoidosis is an inflammatory disease characterized by the formation of lumps called granulomas in the lungs, skin, or lymph nodes. The cause of sarcoidosis is often unknown, but doctors suspect it might be caused by problems in the immune system; the granulomas in the lungs might be caused by an immune reaction to something inhaled into the lungs. Sarcoidosis may not cause symptoms. It is often detected after having a chest x-ray. In most cases, sarcoidosis goes away on its own without any treatment.
Shock caused by sepsis, a condition caused by severe infection resulting in widespread and destructive inflammation of the whole body, often cause a drastic reduction of white blood cells. Some cases of sepsis cause very low white blood cells, sometimes causing to as low as 4000 per microliter.
The bone marrow can become infected by viruses, causing a drop in white blood cell production that results to low blood counts. Bone marrow infection is uncommon, but it can happen due to infection that makes its way into the bloodstream or from injuries near the vicinity of the bone (including bed sores). Some of these viruses cause diseases including parovovirus B19, dengue, hepatitis viruses, Epstein-Barr virus, cytomegalovirus, and the human immunodeficiency virus.
In cancer patients, low white blood cell count is often caused by chemotherapy. Drugs used for treating cancer work by killing rapidly dividing cells that make up tumors. The problem is that the cells in the bone marrow also divide very quickly, and so are targeted by chemotherapy drugs too. Radiation therapy used to kill cancer cells also kill the bone marrow too, causing low white blood cell counts. During cancer treatment, your doctor will order several CBC tests to monitor your white blood cells and will try to prevent them from becoming too low. Your health provider will also monitor you for signs of infection.
It is also to note that some cancers damage the bone marrow and affect your white blood cells. Any cancer can do this once they affect the bones. One particular type of cancer, called acute myeloid leukemia, starts in the bone marrow and may affect the cells that produce white blood cells. Another cancer, multiple myeloma, also causes low white blood cells because it interferes with the production of blood components.
Another cause is genetic or congenital problems that cause diminished bone marrow function, also known as inherited bone marrow failures. It is caused by a problem in the genes. Some of these conditions do not manifest symptoms until adulthood. These conditions include Fanconi anemia, Dyskeratosis congenital, Shwachman-Diamond syndrome, Diamond-Blackfan anemia, Severe congenital neutropenia, and Congenital amegakaryocytic thrombocytopenia. The good thing is that these conditions are relatively rare.
Low white blood cell count can be caused by taking certain antibiotics. It is a side effect reported in many penicillins and cephalosporins, including Penicillin-G, Cefazolin, Cefoxitin, and Cephalothin. It is relatively rare.
4 Treatment for low white blood cell count
If your white blood cell levels are low, among the focus of treatment is prevent infection. Having low white blood cell counts mean that your defenses against infection is also low. You have to stick to seemingly simple yet vital measures, like frequently washing hands, avoiding crowds, not sharing personal items like combs, toothbrush, drinking glasses, eating utensils, or razors. You also should avoid eating raw food and slightly cooked food, which can be full of bacteria. If you are at risk of infection, you must eat thoroughly cooked food only. If you sustained a cut or any minor skin wound, cleanse and apply bandages right away.
Sometimes, we still acquire an infection despite our best efforts. Be on guard for signs and symptoms such as fever and chills, unexplained fatigue, muscle pains, loss of appetite, cough, nasal congestion, stiff neck, pain during urination, and night sweats. If you have any of these, go to the doctor right away.
Low white blood cell count is a feature or sign of a condition, rather than a health problem itself. Therefore, it will go away once the cause is treated. If the cause is an autoimmune disease, inducing remission or reducing risk of infection may help prevent complications.
For HIV infection, taking anti-retroviral drugs kills some of the virus that keeps them from multiplying and overwhelming body’s defenses. Anti-retroviral drugs help delay onset of AIDS, but they have to be taken regularly. Also, you must engage in safe sex, as catching another virus can cause something called superinfection. This often proceeds to AIDS.
Infection in organs like the bone marrow often requires hospitalization. Depending on the agent that causes infection, doctors may prescribe antibiotics, antivirals, or antifungals to treat it. White blood cell numbers will recover once the bone marrow’s integrity is restored. In the case of sepsis, you need to be monitored to prevent onset of shock, which can cause severe organ damage.
Low white blood cell count is often a concern to patients receiving chemotherapy. Doctors will monitor counts by regular CBC. They also adjust the dosage and frequency of the drug to allow the body to rest and white blood cell counts to recover. In cases where white blood cells often become dangerously low, doctors look for other alternative chemotherapy drugs. Antibiotics affecting white blood cell counts are somewhat rare, but it can happen. In that case, the doctor will also change the antibiotic.
There are drugs that can boost white blood cells. They work by making it easier for the bone marrow to produce white blood cells; many of them are just synthetic versions of blood growth factors produced in the body. They are often given to patients having radiation treatment and chemotherapy. Some of these drugs include Filgastrim (Neupogen), Lenograstim (Granocyte) and Pegfilgastrim (Neulasta).
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