The Science Behind Hair Growth Cycles and How Disruption Occur

Hair growth occurs in cycles that consist of three main phases:

Anagen Phase

- This is the active growth phase of hair follicles. - Lasts several years (typically 2 to 7 years) depending on genetics and hair type. - During this phase, hair grows approximately 1 cm per month.

Catagen Phase

- This is a transitional phase that lasts for a few weeks (about 2 to 3 weeks). - Hair growth slows down, and the hair follicle shrinks. - The hair detaches from the blood supply and the dermal papilla.

Telogen Phase

- This is the resting phase that lasts for about 3 to 4 months. - Hair does not grow, but stays attached to the follicle. - At the end of this phase, the hair falls out, and a new anagen phase begins.

How Disruption Occurs i Growth Cycles

Disruption of the hair growth cycle can occur due to various factors:

Genetic Factors

- Conditions such as androgenetic alopecia (male or female pattern baldness) can disrupt normal hair cycles.

Hormonal Changes

- Fluctuations in hormones, particularly androgens, can lead to hair thinning or loss. - Conditions like pregnancy, menopause, or thyroid disorders can impact hair growth.

Physical Stress

- Trauma, surgery, or severe illness can lead to telogen effluvium, where a significant number of hair follicles enter the telogen phase prematurely.

Nutritional Deficiencies

- Lack of essential nutrients such as vitamins (A, D, E), minerals (zinc, iron), and proteins can adversely affect hair growth.

Environmental Factors

- Exposure to pollutants, harsh chemicals, or extreme temperatures can damage hair and disrupt growth cycles.

Medical Conditions

- Conditions like alopecia areata, lupus, or scalp infections can interfere with normal hair growth.

Medications

- Certain medications, particularly those for cancer, depression, or blood pressure, can have side effects that impact hair growth. Understanding these cycles and the factors that can disrupt them is crucial for maintaining healthy hair and addressing hair loss issues effectively.

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