Pathophysiology Essentials: Inflammation, Endocrine, and GI Disorders

Inflammatory vs. Non-Inflammatory Conditions

• Inflammatory: Immune involvement, increased CRP/ESR, pain, redness, and swelling (e.g., RA).
• Non-Inflammatory: Mechanical or degenerative, minimal lab changes (e.g., OA).

Structural Damage and Functional Loss

Tissue damage leads to impaired function (e.g., cirrhosis, fibrosis, portal hypertension).

Hormone Excess vs. Deficiency

• Excess: Overstimulation (e.g., weight loss, tachycardia).
• Deficiency: Slowed systems (e.g., fatigue, weight gain).

Chronic Disease and Multisystem Effects

Long-term inflammation and hormone imbalances affect cardiovascular, renal, neurological, and immune systems.

Autoimmune Targeting

• Thyroid: Metabolic changes.
• Joints: Deformity.
• CNS: Neurological system impairment.

Compensation Mechanisms

Initially maintains homeostasis, but eventually worsens disease (e.g., RAAS in heart failure).

Musculoskeletal Disorders

• Osteoarthritis (OA): Non-inflammatory, cartilage degradation, pain worse with use, bony enlargement.
• Rheumatoid Arthritis (RA): Autoimmune inflammatory, symmetric joint involvement, pannus formation, joint erosion, and deformity.

Bone Remodeling and Fracture Healing

Osteoclasts resorb bone while osteoblasts rebuild it; requires calcium, Vitamin D, and adequate blood supply.

Osteoporosis

Decreased bone density, increased fracture risk, often asymptomatic until a fracture occurs.

Endocrine Disorders

• Addison's Disease: Primary adrenal insufficiency; decreased cortisol/aldosterone, fatigue, hypotension, weight loss. Addisonian crisis is a life-threatening shock.
• Primary vs. Secondary Disorders: Primary: Gland failure (increased tropic hormone). Secondary: Pituitary failure (decreased tropic hormone).

Thyroid Dysfunction

• Hypothyroidism: Increased TSH, decreased T3/T4.
• Hyperthyroidism: Decreased TSH, increased T3/T4.
• Graves' Disease: Autoimmune stimulation causing hyperthyroidism.
• Hashimoto's Thyroiditis: Autoimmune destruction causing hypothyroidism.

Gastrointestinal Disorders

• Cirrhosis: Fibrosis and nodules leading to portal hypertension.
• Portal Hypertension Complications: Ascites, varices, and splenomegaly.
• Hepatic Encephalopathy: Increased ammonia, confusion, asterixis, and coma.
• Crohn's vs. Celiac: Crohn's: Inflammatory, transmural, skip lesions. Celiac: Autoimmune, gluten-triggered, villous atrophy.
• Diverticulosis vs. Diverticulitis: Diverticulosis: Pouches, no inflammation. Diverticulitis: Inflamed, painful, febrile.

Autoimmune Disorders

Lupus (SLE)

Multisystem autoimmune disease affecting skin, joints, kidneys, and CNS due to immune complex deposition. It is multisystem because circulating antibodies affect multiple tissues.

Mental Health

• Schizophrenia: Positive: Hallucinations, delusions. Negative: Flat affect, avolition.
• Bipolar Disorder: Mania: Severe, impaired function. Hypomania: Milder, no major impairment.
• Major Depressive Disorder (MDD): Persistent low mood.