Disease Susceptibility: 10 Key Predisposing Factors

Individual vulnerability to disease arises from an interplay of intrinsic and extrinsic factors. Understanding these enables targeted prevention.

Predisposing Factors

1. Age: Extremes of life — immature immunity in children; immunosenescence, multimorbidity in elderly.
2. Genetics: Polygenic risk scores, monogenic disorders (e.g., BRCA, CFTR), HLA haplotypes affecting infection/autoimmunity.
3. Immune competence: Primary immunodeficiency, HIV, immunosuppressive therapy, malignancy, malnutrition.
4. Nutrition: Deficiencies (vit A, D, Zn, Fe, protein) impair barrier and immune function; obesity = chronic inflammation.
5. Psychosocial stress: Chronic stress → HPA axis dysregulation → suppressed cellular immunity, enhanced inflammation.
6. Environment: Air pollution, heavy metals, endocrine disruptors, allergens, occupational exposures.
7. Lifestyle: Sedentary behavior, smoking, alcohol excess, sleep deprivation, substance use.
8. Chronic disease: Diabetes (impaired neutrophil function), CKD, cirrhosis, COPD, CVD — all increase infection risk.
9. Socioeconomic status: Access to care, nutrition, housing, education, health literacy — fundamental drivers of health inequity.
10. Cultural/behavioral factors: Hygiene practices, dietary traditions, vaccine hesitancy, care-seeking behavior.

Risk is multiplicative, not additive. Precision prevention addresses modifiable factors within each patient's context.