Hair Loss & the Hair Growth Cycle
Understanding How Hair Grows and Why Hair Loss Occurs
Hair loss is often the result of disruptions within the natural hair growth cycle. While shedding is a normal part of healthy hair function, changes in the timing or duration of each phase can lead to thinning, excessive hair loss, or slowed regrowth.
At Bopp Dermatology & Facial Plastic Surgery, we believe that understanding how the hair cycle works is an essential step in identifying the cause of hair loss and choosing the most effective treatment approach.
The Hair Growth Cycle Explained
Each hair follicle follows a continuous cycle of growth, transition, rest, and shedding. This process occurs independently in each follicle, allowing for consistent hair density under normal conditions.
The hair growth cycle consists of three main phases:
- Anagen (Growth Phase)
- Catagen (Transition Phase)
- Telogen (Resting Phase)
TYPES OF CONDITIONS & DISORDERS
Anagen Phase (Growth Phase)
The anagen phase is the active growth stage of the hair follicle. During this phase, cells in the hair root divide rapidly, producing the hair shaft that emerges from the scalp.
Key features of the anagen phase:
- Lasts 2 to 7 years
- Determines hair length and thickness
- Approximately 85–90% of scalp hairs are in this phase at any given time
Healthy hair growth depends on a long, stable anagen phase. Conditions such as male and female pattern baldness can shorten this phase, resulting in thinner, weaker hair and reduced overall density.
Catagen Phase (Transition Phase)
The catagen phase is a brief transitional period that signals the end of active hair growth. During this time, the hair follicle shrinks and detaches from its blood supply.
Key characteristics of the catagen phase:
- Lasts approximately 2–3 weeks
- Hair growth stops
- Follicle prepares to enter the resting phase
Only about 1–2% of scalp hairs are in the catagen phase at any given moment, making this the shortest stage of the hair cycle.
Telogen Phase (Resting Phase)
The telogen phase is the resting stage of the hair growth cycle. While the follicle remains inactive, the existing hair stays in place until it naturally sheds to allow new growth to begin.
Telogen phase details:
- Lasts 2–4 months
- Approximately 10–15% of scalp hairs are in this phase
- Normal daily shedding occurs during this stage
When a higher-than-normal number of hairs enter the telogen phase at once, excessive shedding may occur. This condition is known as telogen effluvium and is often triggered by stress, illness, hormonal changes, or significant life events.
How Hair Loss Develops Within the Growth Cycle
Hair loss occurs when the natural hair cycle becomes imbalanced. Common disruptions include:
- A shortened anagen phase, leading to thinner and shorter hair
- A prolonged telogen phase, causing excessive shedding
- Damage to the follicle that prevents new hair growth
Understanding which phase of the cycle is affected helps guide appropriate treatment and management strategies.
When to Seek Professional Evaluation for Hair Loss
- Excessive or prolonged hair shedding
- Noticeable thinning or reduced hair density
- Hair that no longer grows as long or thick as before
- Sudden changes in hair texture or volume
Early assessment can help identify the cause of hair loss and protect long-term follicle health.
Expert Hair Loss Care at Bopp Dermatology & Facial Plastic Surgery
At Bopp Dermatology & Facial Plastic Surgery, we take a comprehensive, medical approach to diagnosing hair loss and scalp disorders. Our team evaluates the health of the hair follicles, identifies disruptions in the growth cycle, and develops personalized care plans to support healthier hair growth.
Whether hair loss is genetic, hormonal, stress-related, or medical in nature, understanding the hair growth cycle is the foundation for effective treatment.
Schedule a consultation with Bopp Dermatology & Facial Plastic Surgery to learn more about your hair growth cycle and explore solutions for healthier hair.