Atrophic

Atrophic is an adjective used in biology and medicine to describe tissues, organs, or structures that have undergone atrophy— a reduction in size, cell number, or function resulting from disease, disuse, aging, or other adverse conditions. The term is often applied to describe a state rather than a process on its own and is commonly paired with nouns such as mucosa, muscle, or glandular tissue. Atrophic does not imply a specific cause, though it frequently reflects diminished activity or loss of stimulation.

Causes and mechanisms of atrophy include disuse or immobilization, aging, denervation, ischemia, malnutrition, chronic inflammation, and hormonal or metabolic disorders. At the cellular level, atrophy involves decreased protein synthesis and increased protein degradation, frequently via pathways such as the ubiquitin-proteasome system or autophagy. It can also involve a reduction in cell size or, in some tissues, loss of cells and tissue architecture. The result is a lighter, thinner, or weaker tissue with reduced functional capacity.

Examples of atrophic states occur in various organ systems. Muscular atrophy can arise from prolonged inactivity, aging (sarcopenia), or neurogenic injury. Gastric mucosal atrophy (atrophic gastritis) involves loss of gastric glands and thinning of the mucosa. Cutaneous (skin) atrophy may accompany aging or chronic corticosteroid use. Brain and other organ atrophy are observed in several neurodegenerative or chronic disease conditions.

Diagnosis and management focus on addressing the underlying cause, improving nutrition, and implementing rehabilitation or physical therapy when possible. Some atrophic changes may be irreversible if structural loss is extensive.