Male Pattern Baldness

What is Male Pattern Baldness?

Androgenetic Alopecia (AGA), commonly known as Male Pattern Baldness (MPB), is the most prevalent form of progressive hair loss, characterised by a distinct Pattern of Loss in the vertex, mid-scalp, and frontal regions [1]. The condition is fundamentally a genetically predetermined disorder, meaning a Genetic Predisposition is a required attribute for its manifestation. This predisposition determines an individual’s Hormonal Sensitivity to androgens, which is the core driver of the condition [1].

What Is the Norwood Scale?

The Norwood Scale (also known as the Hamilton-Norwood Scale) is the leading classification system used by medical professionals to assess the extent and progression of male pattern baldness (Androgenetic Alopecia). It provides a standardised visual reference of 7 distinct stages, from a full head of hair to extensive baldness. This enables accurate diagnosis, effective treatment planning, and clear communication between doctors and patients regarding hair loss severity.

Why is the Norwood Scale so important?

Before the Norwood Scale was standardised by Dr O’Tar Norwood in the 1970s, describing male hair loss was subjective and inconsistent. The scale’s introduction revolutionised the field of hair restoration for several key reasons:

1. Standardised Diagnosis
It provides a universal language for clinicians. A “Norwood Stage 4” means the same thing to a dermatologist in London as it does to a hair transplant surgeon in Melbourne.

2. Treatment Planning
The scale is crucial for determining the most appropriate course of action. Treatments that are highly effective at Stage 3 may be unsuitable or insufficient at Stage 6.

3. Managing Expectations
It allows a doctor to show a patient where they are on the hair-loss journey and discuss realistic outcomes for treatments such as medication or surgery.

4. Tracking Progression
By identifying a patient’s current stage, it’s possible to monitor hair loss over time, helping gauge the effectiveness of preventive treatments.

 

What Causes Male Pattern Baldness?

Male pattern baldness is not just about getting older. It occurs when a specific hormone in your body begins to affect your hair follicles. Here is how it works in plain terms.

Your body naturally produces testosterone, the primary male hormone. An enzyme called 5-alpha-reductase converts some of this testosterone into a more potent hormone called dihydrotestosterone (DHT). DHT is actually much more powerful than regular testosterone when it comes to binding to receptors in your body.

If you have inherited the genes for male pattern baldness from your parents, the hair follicles on the top and front of your scalp are susceptible to DHT. When DHT binds to these follicles, they shrink over time. This shrinking process is called hair follicle miniaturisation. As your follicles get smaller, they produce thinner, shorter, and lighter-colored hairs. Eventually, they may stop producing visible hair altogether.

 

The good news is that DHT does not affect all your hair follicles equally. The hair on the sides and back of your head is usually resistant to DHT, which is why men with advanced hair loss often still have a horseshoe pattern of hair remaining. This becomes particularly important when considering hair transplant procedures, as these DHT-resistant hairs can be relocated to balding areas where they will continue to grow permanently.

 

Why Does It Happen to Some Men and Not Others?

Genetics plays the most significant role. If your father or grandfather experienced hair loss, you are more likely to experience it too. The condition is polygenic, meaning multiple genes from both sides of your family contribute to your risk.

The age at which your hair loss starts and how quickly it progresses vary widely from person to person. Some men start noticing thinning in their twenties, while others do not see significant changes until their forties or fifties. Generally, earlier onset tends to indicate faster, more extensive hair loss, though this is not always the case.

Comparing Your Options: Which Treatment Is Right for You?

Choosing between medications and hair transplant procedures depends on several factors, including your stage of hair loss, your goals, your budget, and your willingness to commit to ongoing treatment.

References

[1] Ho, C. H., Sood, T., & Zito, P. M. (2024). *Androgenetic Alopecia*. StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK430924/