Osteoporosis

Systemic skeletal disorder characterized by reduced bone mass and deterioration of bone microarchitecture, resulting in increased bone fragility and a higher risk of low-trauma (fragility) fractures, particularly affecting the vertebrae, hip, and distal radius.

Causes

• Hormonal and endocrine causes

  • Declining estrogen levels (postmenopausal osteoporosis)

  • Reduced testosterone levels (male hypogonadism)

  • Hyperthyroidism

  • Hyperparathyroidism

  • Cushing syndrome

  • Hypogonadism due to pituitary, hypothalamic, or gonadal disorders

• Aging-related reduction in osteoblast activity

• Medication-related causes

  • Long-term corticosteroid therapy

  • Anti-seizure medications (phenytoin, phenobarbital)

  • Proton pump inhibitors (PPIs)

  • Chemotherapy

  • Aromatase inhibitors

  • Certain immunosuppressive medications

• Nutritional causes

  • Calcium deficiency

  • Vitamin D deficiency

  • Low body weight

  • Protein deficiency

  • Malnutrition

  • Eating disorders

• Gastrointestinal and malabsorption causes

  • Celiac disease

  • Inflammatory bowel disease (Crohn's disease, ulcerative colitis)

  • Chronic pancreatitis or other malabsorption disorders

  • Bariatric surgery-related nutrient deficiency

• Inflammatory and autoimmune causes

  • Rheumatoid arthritis

  • Chronic inflammatory diseases with increased cytokine-mediated bone resorption

  • Systemic autoimmune disorders

• Renal and hepatic causes

  • Chronic kidney disease (renal osteodystrophy)

  • Chronic liver disease affecting vitamin D metabolism and bone turnover

• Malignant causes

  • Multiple myeloma

  • Metastatic bone disease

• Lifestyle-related causes

  • Prolonged physical inactivity

  • Immobilization

  • Heavy alcohol consumption

  • Tobacco smoking

  • Low sunlight exposure leading to reduced vitamin D synthesis

• Osteogenesis imperfecta