[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Aging](https://durgical.com/en/general-pathology/#a-aging) › How organs age: normal changes vs disease [General pathology](https://durgical.com/en/general-pathology/) · [Aging](https://durgical.com/en/general-pathology/#a-aging) # How organs age: normal changes vs disease - Topic Organs lose reserve with age. Knowing what is normal aging and what is disease avoids both overtreatment and missed diagnoses. Updated 2026-11-01 ## Key points - The defining feature of organ aging is loss of reserve, not failure at rest. - GFR falls with age while serum creatinine may stay normal, because muscle mass also falls; drug clearance is slower. - Arterial stiffening raises systolic pressure and pulse pressure. - Sarcopenia and bone loss underlie frailty, falls and fractures. - Presbyopia, presbycusis and cataract are the common sensory changes. ## What it is With age, organs lose part of their reserve capacity, although they work well at rest. The heart stiffens, arteries harden, lungs lose elastic recoil, kidneys filter less, muscles and bones lose mass, and the senses decline. These changes make older adults more vulnerable to stress (infection, surgery, medicines). They are not diseases in themselves, but they lower the threshold for disease. ## Key facts - Immunosenescence weakens vaccine responses and raises the risk of severe infections. - Thinner skin with less collagen tears and bruises easily. - Body water falls and fat rises, changing drug distribution. ## Normal aging vs related disease | Organ | Normal aging | Related disease | | --- | --- | --- | | Heart | Stiffer left ventricle, lower maximum heart rate, valve thickening and calcification | Calcific aortic stenosis, heart failure | | Arteries | Stiffer walls, higher systolic pressure | Isolated systolic hypertension, atherosclerosis | | Lungs | Less elastic recoil, more residual volume, weaker cough | COPD, pneumonia | | Kidneys | Fewer nephrons, lower GFR | Chronic kidney disease, drug toxicity | | Brain | Mild atrophy, slower processing, preserved daily function | Dementia, delirium | | Muscle | Less muscle mass and strength | Sarcopenia, frailty | | Bone | Gradual bone loss, faster after menopause | Osteoporosis, fractures | | Eye | Stiffer lens (presbyopia) | Cataract, macular degeneration | | Ear | Loss of high-frequency hearing | Presbycusis with communication difficulty | ## Clinical notes - Polypharmacy is especially risky in older adults because of reduced kidney and liver reserve. - Atypical presentations (confusion, falls) are common in infections and heart attacks in older adults. ## Memory aid Aging trims the reserve, not the resting power: the engine idles fine but cannot climb steep hills. ## Test yourself Think of the answer, then tap the question to see it. ## Why can serum creatinine stay normal while GFR falls in older adults? Creatinine production falls with the loss of muscle mass, masking the drop in filtration. ## What is the hallmark of organ aging? Loss of functional reserve: organs work at rest but cope poorly with stress. ## Which change in the lens causes difficulty reading up close with age? The lens stiffens and loses accommodation (presbyopia). [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/general-pathology/how-organs-age-normal-changes-vs-disease/) ## Related - [Cellular aging: telomeres, DNA damage, senescence and proteostasis](https://durgical.com/en/general-pathology/cellular-aging-telomeres-dna-damage-senescence-and-proteostasis/) - [Atrophy](https://durgical.com/en/general-pathology/atrophy/) - [Pigments in tissue: lipofuscin, hemosiderin, melanin, bilirubin, carbon](https://durgical.com/en/general-pathology/pigments-in-tissue-lipofuscin-hemosiderin-melanin-bilirubin-carbon/) - [Pathologic calcification: dystrophic vs metastatic](https://durgical.com/en/general-pathology/pathologic-calcification-dystrophic-vs-metastatic/) ## Related conditions - [Frailty syndrome](https://durgical.com/en/conditions/frailty-syndrome/) - [Sarcopenia](https://durgical.com/en/conditions/sarcopenia/) - [Osteoporosis](https://durgical.com/en/conditions/osteoporosis/) - [Presbycusis (age-related hearing loss)](https://durgical.com/en/conditions/presbycusis/) - [Cataract](https://durgical.com/en/conditions/cataract/) - [Dementia (major neurocognitive disorder)](https://durgical.com/en/conditions/dementia/) - [Mild cognitive impairment](https://durgical.com/en/conditions/mild-cognitive-impairment/) - [Falls in older adults](https://durgical.com/en/conditions/falls-in-older-adults/) - [Polypharmacy and potentially inappropriate medications in older adults](https://durgical.com/en/conditions/polypharmacy-and-potentially-inappropriate-medications-in-older-adults/) - [Chronic kidney disease](https://durgical.com/en/conditions/chronic-kidney-disease/) - [Aortic Valve Stenosis](https://durgical.com/en/conditions/aortic-valve-stenosis/) - [Refractive errors and presbyopia](https://durgical.com/en/conditions/refractive-errors-and-presbyopia/) - [Age-related macular degeneration](https://durgical.com/en/conditions/age-related-macular-degeneration/) - [Chronic obstructive pulmonary disease (COPD)](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/) ## Elsewhere in DurgiPedia - [Menopause](https://durgical.com/en/physiology/menopause/) - [Optics of the eye, accommodation and refractive errors](https://durgical.com/en/physiology/optics-of-the-eye-accommodation-and-refractive-errors/) - [Hearing: middle ear, cochlea and auditory pathway](https://durgical.com/en/physiology/hearing-middle-ear-cochlea-and-auditory-pathway/) - [Bone remodeling](https://durgical.com/en/physiology/bone-remodeling/) - [Vascular compliance and capacitance](https://durgical.com/en/physiology/vascular-compliance-and-capacitance/) - [Glomerular filtration: the barrier and its determinants](https://durgical.com/en/physiology/glomerular-filtration-the-barrier-and-its-determinants/) [← 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: [Aging changes in organs, tissue and cells: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/004012.htm) (MedlinePlus, US National Library of Medicine, 2024); [Aging changes in the bones - muscles - joints: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/004015.htm) (MedlinePlus, US National Library of Medicine, 2024); [Presbycusis](https://www.ncbi.nlm.nih.gov/books/NBK559220/) (StatPearls (NCBI Bookshelf), 2024); [Cataract](https://www.ncbi.nlm.nih.gov/books/NBK539699/) (StatPearls (NCBI Bookshelf), 2024). ## **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/how-organs-age-normal-changes-vs-disease/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/how-organs-age-normal-changes-vs-disease/