Metabolic diseases and disorders arise from disruptions in the biochemical processes responsible for energy production, nutrient utilization, and waste elimination. These can result from genetic defects, hormonal imbalances, nutrient deficiencies, or environmental factors. Some are inherited, while others are acquired.
| Disease / Disorder | Metabolic Dysfunction | Notes / Evidence |
| Type 1 Diabetes Mellitus | Autoimmune destruction of pancreatic beta cells leads to absolute insulin deficiency. | Requires lifelong insulin therapy; early detection prevents ketoacidosis. |
| Type 2 Diabetes Mellitus | Insulin resistance and relative insulin deficiency cause chronic hyperglycemia. | Linked to obesity, sedentary lifestyle; managed with diet, exercise, medication. |
| Metabolic Syndrome | Cluster of insulin resistance, dyslipidemia, hypertension, and abdominal obesity. | Increases risk for cardiovascular disease and type 2 diabetes. |
| Hyperthyroidism | Excess thyroid hormones increase metabolic rate and energy expenditure. | Commonly caused by Graves’ disease; treated with medication, radioiodine, or surgery. |
| Hypothyroidism | Insufficient thyroid hormones slow metabolic processes. | Often due to Hashimoto’s thyroiditis; treated with thyroid hormone replacement. |
| Cushing’s Syndrome | Excess cortisol disrupts carbohydrate, protein, and fat metabolism. | Caused by prolonged steroid use or adrenal/pituitary tumors. |
| Addison’s Disease | Deficient cortisol and aldosterone impair energy metabolism and fluid balance. | Requires lifelong hormone replacement. |
| Inborn Errors of Metabolism | Genetic enzyme defects impair specific metabolic pathways (e.g., PKU, maple syrup urine disease). | Often detected by newborn screening; managed with diet and supplements. |
| Obesity | Chronic positive energy balance with hormonal dysregulation (e.g., leptin resistance). | Increases risk for multiple metabolic and cardiovascular diseases. |
| Glycogen Storage Diseases | Defects in enzymes regulating glycogen synthesis or breakdown impair glucose homeostasis. | Types vary in severity; some cause hypoglycemia, muscle weakness. |