Breast atrophy is the partial or complete loss of glandular and adipose volume within the mammary envelope, most frequently encountered after substantial weight reduction, menopause, prolonged hypo-oestrogenism, or post-operative/radiation changes. Recognition is based on objective volume loss rather than subjective patient perception.

1. Decrease in breast projection and circumference
   Measurable reduction in bust circumference (> 2 cm compared with baseline) and loss of upper-pole fullness produce a flattened or “deflated” contour.
2. Excess, lax skin envelope
   The mammary skin becomes redundant, often with fine wrinkling and loss of elasticity; the inframammary fold may descend or efface.
3. Nipple-areolar complex changes
   Areolar diameter often decreases, and the nipple may assume a more pendulous position relative to the chest wall; true nipple retraction is absent unless malignant scarring co-exists.
4. Asymmetry when unilateral
   Following surgery or radiotherapy, the affected side appears visibly smaller, with contralateral compensatory hypertrophy accentuating disparity.
5. Loss of breast tenderness and cyclical variation
   Post-menopausal involution abolishes the premenstrual fullness and mastalgia previously experienced; sudden recurrence of pain merits investigation for pathology.
6. Associated systemic stigmata
   Generalised thinning of scalp hair, dry skin, and hot flushes accompany physiological or premature menopause; concurrent loss of axillary/pubic hair suggests pan-hypopituitarism.
7. Psychosocial impact
   Significant distress, avoidance of fitted clothing, and altered body image are common; some patients request reconstructive augmentation or autologous fat grafting.
8. Absence of underlying mass
   On palpation and imaging, only fatty replacement and fibrous strands are evident; any discrete nodule within an atrophic breast requires malignancy exclusion.