What are the anatomical names of the vaginal lips, and how do they change with aging?

Anatomical Nomenclature and Age-Related Changes of the Vaginal Lips

Anatomical Names

The external female genital structures commonly referred to as "vaginal lips" are formally termed the labia majora (outer lips) and labia minora (inner lips), which together with the clitoris, mons pubis, and perineum comprise the vulva or pudendum femininum. 1, 2

Specific Anatomical Structures

• The labia majora are the larger, outer folds of skin and adipose tissue that form the lateral boundaries of the vulva 3, 2
• The labia minora are the smaller, inner folds of hairless skin located medial to the labia majora, extending from the clitoral hood anteriorly to the posterior fourchette 4, 3
• These structures collectively form part of the vulva (also called the pudendum femininum or pudendum muliebre), which encompasses all external female genital structures 1, 2

Important Terminology Clarification

• The term "pudendum" historically carries positive connotations related to respect, modesty, honor, and veneration—not shame as commonly misinterpreted—and applies to external genitalia regardless of sex 1
• The vagina itself is an internal structure and distinct from the vulva; confusion between these terms is common but anatomically incorrect 2

Age-Related Changes in Labial Anatomy

The labia minora demonstrate significant age-related changes, with length inversely correlated with age (r = -0.364, P < 0.001), meaning they become shorter as women age. 5

Specific Age-Related Anatomical Changes

• Labial length decreases progressively with aging, particularly affecting the labia minora which show the most pronounced inverse correlation with age 5
• The perineum also shortens with age (r = -0.095, P = 0.014), though less dramatically than the labia minora 5
• Postmenopausal hormonal changes cause vulvovaginal atrophy with thinning, drying, and loss of tissue elasticity affecting both the labia and surrounding vulvar structures 6

Pathological Age-Related Changes

• Lichen sclerosus, which has a bimodal distribution with peaks in prepubertal girls and postmenopausal women, causes progressive scarring with fusion of the labia minora, loss of labial architecture, and narrowing of the introitus 7
• The condition presents with porcelain-white papules and plaques affecting the interlabial sulci, labia minora, and clitoral hood, with characteristic figure-eight pattern around the vulva and anus 7
• Untreated lichen sclerosus carries increased risk of progression to squamous cell carcinoma, making recognition and treatment critical 8

Hormonal Effects on Vulvar Tissue

• Low serum estrogen causes vaginal and vulvar atrophy with higher vaginal pH, reduced lubrication, and tissue fragility 6
• Pelvic irradiation impairs blood flow to the vagina and vulva, causing scarring and tissue changes 6
• Vestibular gland function may be affected by surgery, irradiation, or aging, contributing to dryness 6

Clinical Implications

• For symptomatic vulvovaginal atrophy, a stepwise approach begins with lubricants and vaginal moisturizers applied three to five times per week to the vagina, vaginal opening, and external vulvar folds 6
• When conservative measures fail, low-dose vaginal estrogen is recommended, even in women with hormone-positive breast cancer after thorough discussion of risks and benefits 6
• Body mass index positively correlates with labia majora length (r = 0.150, P < 0.001) and introitus length (r = 0.097, P = 0.014), indicating weight affects vulvar dimensions 5

Important Clinical Pitfall

• Wide variation exists in normal vulvar morphology across all ages, making it critical to avoid pathologizing normal anatomical diversity when evaluating patients 4, 3, 5