Factors that affect hair growth can include congenital issues, hormonal influences, and which of the following?

Factors that affect hair growth are quite diverse, and each can significantly influence how hair develops and cycles through growth phases. In this context, medical disorders are a critical factor because they encompass a wide range of conditions that can directly impact hair follicles and hair production.

Certain medical disorders, such as thyroid dysfunction, alopecia areata, and scalp infections, can alter hormone levels, lead to inflammation, or damage hair follicles. For instance, thyroid problems may cause hair thinning or loss, while conditions like polycystic ovary syndrome (PCOS) can lead to excess hair growth in unwanted areas due to hormonal imbalances. Understanding the interplay between various medical issues and hair growth is essential for addressing hair loss or excessive growth effectively.

While the other options, such as dietary changes, cosmetic practices, and environmental factors, can influence hair health, they do not have as direct or significant impact as medical disorders do. Changes in diet can affect hair health overall but are less likely to cause systemic changes that lead to hair growth issues. Cosmetic practices like frequent styling or treatments can affect the hair's appearance but usually do not alter the growth process itself. Environmental factors, while they can affect hair condition due to exposure to elements, do not directly influence the biological mechanisms governing