Which factor is most likely to cause systemic hair growth changes?

• A. Scalp Irritation
• B. Hormonal Changes
• C. Hair Styling
• D. Sun Exposure

Answer: (B)

Systemic hair growth changes are driven by circulating hormones that regulate the hair growth cycle across the body. Hormones influence how long hair stays in the growth phase and when it moves into shedding, so shifts in hormonal balance can alter hair density and shedding all over, not just in one spot. That broad, body-wide regulation is what makes hormonal changes the most likely cause of systemic changes to hair growth. Local scalp irritation affects only the area it touches, hair styling causes damage largely from mechanical stress to the hair, and sun exposure mainly affects the hair and scalp surface rather than the body's overall hair growth pattern.