Smokers may experience an elevated white blood cell count for a variety of reasons. Smoking can cause and/or worsen many medical problems, such as cardiac, respiratory and dental conditions. Cigarette smoke is also a known carcinogen and a leading cause of many different cancers. Patients suffering from these and other illnesses affected by smoking may present with a high white blood cell count.
What is an Elevated WBC Count?
An elevated white blood cell count, or WBC count, occurs when white blood cells, called leukocytes, attempt to fight infection in the body. When the body detects an infection, more leukocytes are produced to combat the problem. A high WBC count can also be caused by certain medications, stress and tissue damage or inflammation. Smoking alone may also increase leukocyte levels as a bodily response to the components of cigarette smoke. Normal WBC lab values range from 4,500 to 10,000 cells/ml.
Smoking is one of the leading causes of cardiovascular disease in the United States. According to the American Heart Association, smokers are at a greater risk of developing atherosclerosis, which can lead to heart attack, coronary heart disease and stroke. Atherosclerosis, a build-up of fatty substances in the arteries, occurs due to changes in the walls of blood vessels caused by the chemicals found in cigarettes. Smokers suffering from atherosclerosis will have an elevated WBC count on examination due to inflammation occurring within the blood vessel walls.
Infections and Inflammation
An elevated WBC count is expected when infections or inflammation occurs within the body. Smokers are prone to frequent respiratory infections, sinusitis, chronic obstructive pulmonary disease, emphysema and chronic bronchitis. Cigarette smoke also aggravates certain conditions such as asthma. Additionally, smoking can lead to dental problems such as tooth decay, gum disease, oral abscesses and ulcers, all of which can result in an increased WBC count secondary to either infection or swelling.
Smokers are at an increased risk of developing cancer. The carcinogens found in cigarette smoke are known to cause lung, mouth and throat cancer. Smokers are also prone to developing pancreatic, bladder, esophageal and kidney cancer. Inflammation caused by smoking is believed to be one of the factors in the development of these cancers and therefore should be evaluated when a smoking patient presents with an elevated WBC count.
A study by T. Erlinger, P. Muntner and K. Helzlsouer published in "The Journal of Cancer Epidemiology, Biomarkers and Prevention" in 2004 hypothesized that inflammation—as reflected by elevated WBC—would be associated with increased risk of cancer mortality in a national sample of U.S. adults. The study found evidence linking inflammation (whether caused by smoking or some other inflammatory agent) to an increased cancer risk. The study also stated that tobacco smoke, "a well-known carcinogen, increases several markers of inflammation, including WBC. While smoking may have direct carcinogenic effects, it is also conceivable that the general inflammatory response induced by smoking could increase risk of cancers."
Things to Consider
Whether an elevated WBC count has already been detected in a smoking patient, it is never too late to quit smoking. According to the American Cancer Society, quitting prior to age 50 cuts the risk of dying within the next 15 years in half. Ex-smokers also suffer from fewer illnesses such as bronchitis and pneumonia and typically enjoy a better quality of life than smokers. Smokers experiencing an elevated WBC count should be evaluated by their physician to determine the underlying cause and necessary course of treatment.