[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Cell injury, adaptation and death](https://durgical.com/en/general-pathology/#a-injury) › Hypertrophy: physiologic and pathologic [General pathology](https://durgical.com/en/general-pathology/) · [Cell injury, adaptation and death](https://durgical.com/en/general-pathology/#a-injury) # Hypertrophy: physiologic and pathologic - Process Hypertrophy is growth of an organ because its cells get bigger, not more numerous. The heart and muscles do this when they work harder. Updated 2026-11-01 ## Key points - Larger cells, not more cells; seen especially in cells with little capacity to divide (cardiac and skeletal muscle). - Triggers: mechanical stretch, growth factors (IGF-1) and agonists (angiotensin II, alpha-adrenergic signals). - The myocyte switches on a fetal gene program (beta-myosin heavy chain, natriuretic peptides). - Pressure overload causes concentric hypertrophy; volume overload causes eccentric hypertrophy. - The pregnant uterus enlarges by both hypertrophy and hyperplasia of smooth muscle. ## What it is Hypertrophy is an increase in cell size, with more structural proteins and organelles, that enlarges the organ. It is typical of cells that divide little, such as heart and skeletal muscle. It can be physiologic (athletes, the pregnant uterus) or pathologic (heart under pressure or volume overload). Hypertrophy has a limit: an overloaded heart eventually develops myocyte injury, fibrosis and failure. ## Structure - Gross: thick ventricular wall; heavy heart. - Microscopic: enlarged myocytes with large, dark, often box-shaped nuclei. - In hypertrophic cardiomyopathy: myocyte disarray and interstitial fibrosis. ## Step by step - Workload rises (high blood pressure, aortic stenosis, exercise) and stretches the myocytes. - Stretch sensors, growth factors and hormones activate intracellular signalling. - Transcription factors (such as GATA4, NFAT and MEF2) switch on growth genes. - More contractile proteins and sarcomeres are made; the cell enlarges and generates more force. - If overload persists, capillary supply and energy production lag behind. - Myocytes degenerate, fibrosis develops and the ventricle stiffens and fails. ## Physiologic vs pathologic hypertrophy of the heart | Feature | Physiologic (athlete) | Pathologic (disease) | | --- | --- | --- | | Cause | Training, intermittent load | Chronic pressure or volume overload, mutations | | Function | Normal or better | Diastolic dysfunction, then systolic failure | | Fibrosis | No | Yes | | Reversibility | Regresses when training stops | Partly reversible if the cause is treated early | | Gene program | Adult isoforms preserved | Fetal genes re-expressed | ## Clinical notes - Left ventricular hypertrophy from hypertension is an independent risk factor for heart failure, arrhythmia and sudden death. - Hypertrophic cardiomyopathy is inherited (usually sarcomere gene mutations) and a cause of sudden death in young athletes. ## Memory aid Hypertrophy is the bodybuilder: same team, bigger players. Hyperplasia is recruiting: more players on the team. ## Test yourself Think of the answer, then tap the question to see it. ## Why does the heart respond to overload by hypertrophy rather than hyperplasia? Adult cardiac myocytes have very limited capacity to divide, so they adapt by enlarging. ## What type of hypertrophy does chronic hypertension cause? Concentric left ventricular hypertrophy, with a thick wall and normal or small chamber. ## What changes mark pathologic rather than physiologic cardiac hypertrophy? Fibrosis, re-expression of fetal genes and progressive dysfunction leading to heart failure. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/general-pathology/hypertrophy-physiologic-and-pathologic/) ## Related - [Hyperplasia: physiologic and pathologic](https://durgical.com/en/general-pathology/hyperplasia-physiologic-and-pathologic/) - [Atrophy](https://durgical.com/en/general-pathology/atrophy/) - [Metaplasia](https://durgical.com/en/general-pathology/metaplasia/) - [Intracellular accumulations: cholesterol, proteins, hyaline, glycogen](https://durgical.com/en/general-pathology/intracellular-accumulations-cholesterol-proteins-hyaline-glycogen/) ## Related conditions - [Hypertensive heart disease](https://durgical.com/en/conditions/hypertensive-heart-disease/) - [Hypertrophic cardiomyopathy](https://durgical.com/en/conditions/hypertrophic-cardiomyopathy/) - [Arterial hypertension](https://durgical.com/en/conditions/arterial-hypertension/) - [Aortic Valve Stenosis](https://durgical.com/en/conditions/aortic-valve-stenosis/) - [Heart failure](https://durgical.com/en/conditions/heart-failure/) - [Pulmonary hypertension and cor pulmonale](https://durgical.com/en/conditions/pulmonary-hypertension-and-cor-pulmonale/) - [Acromegaly and gigantism](https://durgical.com/en/conditions/acromegaly-and-gigantism/) - [Coarctation of the aorta](https://durgical.com/en/conditions/coarctation-of-the-aorta/) ## Elsewhere in DurgiPedia - [Cell adaptations: hypertrophy, hyperplasia, atrophy, metaplasia](https://durgical.com/en/histology/cell-adaptations-hypertrophy-hyperplasia-atrophy-metaplasia/) - [Muscle hypertrophy, atrophy and remodeling](https://durgical.com/en/physiology/muscle-hypertrophy-atrophy-and-remodeling/) - [Heart failure physiology](https://durgical.com/en/physiology/heart-failure-physiology/) - [Preload, afterload and contractility](https://durgical.com/en/physiology/preload-afterload-and-contractility/) - [Physiology of hypertension](https://durgical.com/en/physiology/physiology-of-hypertension/) - [Cardiac muscle: intercalated discs](https://durgical.com/en/histology/cardiac-muscle-intercalated-discs/) - [Smooth muscle](https://durgical.com/en/histology/smooth-muscle/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Hypertensive heart disease: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000163.htm) (MedlinePlus, US National Library of Medicine, 2024); [Hypertrophic cardiomyopathy: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000192.htm) (MedlinePlus, US National Library of Medicine, 2024); [4.6 Tissue Injury and Aging](https://openstax.org/books/anatomy-and-physiology-2e/pages/4-6-tissue-injury-and-aging) (OpenStax (Rice University), 2022). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/hypertrophy-physiologic-and-pathologic/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/hypertrophy-physiologic-and-pathologic/