A predisposing factor is a condition or situation that may make a person more at risk or susceptible to disease. Some predisposing factors include heredity, age, gender, environment, and lifestyle.

Heredity is a predisposing factor when a trait inherited from a parent puts an individual at risk for certain diseases. Cystic fibrosis (ICD-9: 277.00), sickle cell anemia (ICD-9: 282.60), and Down syndrome (ICD-9: 758.0) are examples of hereditary diseases related to genetic abnormalities. If hereditary risks are known, individuals can be better prepared to prevent, treat, or cope with possible problems.

Age is a risk factor related to the life cycle. For example, adenoid hyperplasia (ICD-9: 474.12), acute tonsillitis (ICD-9: 463), and otitis media (ICD-9: 382.9) are more common among children than adults. Older adults are at greater risk than younger adults for degenerative arthritis (ICD-9: 715.9) and senile dementia (ICD-9: 290.0). Elderly persons have unique problems that arise from the aging process itself. Physiological changes occur in the body systems, and some of these changes can cause functional impairment. Elderly persons experience problems with temperature extremes, have lowered resistance to disease as the result of decreased immunity, and have less physical activity tolerance.

Gender is a predisposing factor when the disease is physiologically based. For example, prostate cancer (ICD-9: 185, 198.82, 233.4) occurs only in men; ovarian cancer (ICD-9: 183, 198.6, 233.39) occurs only in women. Men have gout (ICD-9: 274.0) more frequently than do women, whereas osteoporosis (ICD-9: 733.00) is more common in women. Lung cancer (ICD-9: 162.9, 197.0, 231.2) is as prevalent in women as in men. Also, women experience heart disease as often as do men.

The environment can be a risk factor. Exposure to air, noise, and other environmental pollutants may predispose individuals to disease. For example, living close to a heavily traveled thoroughfare in a city may be a predisposition to respiratory disease.

Some geographical locations have a higher incidence of insect bites and exposure to venom. Living in rural areas where fertilizers and pesticides are ommonly used can predispose individuals to disease. Conditions and diseases once endemic to only one area of the world are crossing borders to invade an unsuspecting and unprepared society. This invasion is due largely to the increased mobility of the world’s inhabitants and population density. Even office employees may be affected by environmental or occupational health problems, as seen in carpal tunnel syndrome (ICD-9: 354.0) and eye problems that can result from heavy computer use.

Lifestyle choice may predispose some diseases. Smoking and exposure to secondhand smoke is known to be a major cause of lung cancer. Substance abuse leads to a number of illnesses. Poor nutritional choices and lack of exercise are often cited as predispositions to diseases and disorders.