Androgenetic Alopecia

Overview

Androgenetic alopecia is the most common cause of hair loss, affecting both men and women. It is often called male pattern baldness or female pattern hair loss, depending on the typical pattern it follows. The condition is inherited and is driven by a combination of genetic predisposition and the effect of hormones called androgens on the hair follicles. Over time, affected follicles shrink and produce finer, shorter hairs, until eventually they may stop producing visible hair altogether.

This is a gradual, progressive process that usually begins in adulthood and becomes more common with age. In men it often produces a receding hairline and thinning at the crown, while in women it usually causes diffuse thinning across the top of the scalp with a widening part, rather than complete baldness. Androgenetic alopecia is not dangerous to physical health, but it can affect confidence and well-being, and several treatments can slow the loss or partially regrow hair.

Symptoms

Androgenetic alopecia develops slowly and in recognizable patterns:

• In men: A receding hairline, often starting at the temples to form an "M" shape, along with thinning at the crown that may progress to partial or complete baldness on top.
• In women: Diffuse thinning over the top and crown of the scalp, often first noticed as a widening of the part, while the frontal hairline is usually preserved.
• General features: Hair becomes progressively finer and shorter in the affected areas, and the scalp may become more visible.

The hair loss is usually painless and not accompanied by scarring, redness, or scaling. Sudden, patchy, or rapidly progressing hair loss, or hair loss with scalp symptoms, suggests a different cause and should be evaluated.

Causes

Androgenetic alopecia results from a combination of inherited genes and the action of androgen hormones on the hair follicles:

• Genetics: A family history of pattern hair loss is the strongest factor, and the tendency can be inherited from either side of the family.
• Androgens: Hormones, particularly a derivative of testosterone, cause genetically susceptible follicles to gradually shrink over repeated growth cycles.

As follicles miniaturize, each hair grows for a shorter time and emerges thinner, until the follicles produce only fine, barely visible hair or none at all. In women, pattern hair loss can become more noticeable around menopause due to hormonal changes. It is important to note that everyday factors like washing, brushing, and most hairstyles do not cause this type of hair loss.

Risk Factors

• A family history of pattern hair loss in male or female relatives
• Increasing age
• Being male, with earlier onset and more extensive loss on average
• Hormonal changes in women, such as around menopause
• Conditions associated with higher androgen levels, such as polycystic ovary syndrome in some women

Diagnosis

Androgenetic alopecia is usually diagnosed from the pattern of hair loss and the history. A clinician may:

• Examine the scalp and the distribution of thinning, which is often characteristic.
• Ask about family history, the timeline of hair loss, and any associated symptoms.
• Use a dermatoscope to look closely at the follicles and hair thickness.
• Order blood tests to check for other causes of hair loss, such as thyroid problems, iron deficiency, or hormonal conditions, especially in women.
• Rarely, perform a scalp biopsy if the diagnosis is uncertain.

Treatment

Treatment cannot cure androgenetic alopecia, but several options can slow the loss and partially regrow hair, and they work best when started early:

• Topical minoxidil: A solution or foam applied to the scalp that can slow loss and promote regrowth in many people, used by both men and women.
• Oral medication: A prescription medicine that blocks the hormone driving the process is used in men, and other hormone-related treatments may be used in women.
• Procedures: Options such as low-level laser therapy and, for suitable candidates, hair transplant surgery.
• Cosmetic approaches: Hairstyles, fibers, wigs, or hairpieces to camouflage thinning.

Treatments generally need to be continued to maintain their effect, since stopping usually allows the loss to resume. A doctor or dermatologist can help choose the safest, most suitable option.

Prevention

Because androgenetic alopecia is inherited, it cannot be fully prevented. However, you can slow its progression and protect your existing hair:

• Start treatment early, when it tends to be most effective
• Treat any other contributing conditions, such as thyroid problems or iron deficiency
• Avoid tight hairstyles and harsh treatments that can add to hair loss
• Maintain a balanced diet that supports general hair health
• See a dermatologist promptly if you notice thinning, rather than waiting

When to See a Doctor

Consider seeing a doctor or dermatologist if hair thinning bothers you or you want to slow it, as early treatment works best. It is particularly important to seek evaluation if you have:

• Sudden, rapid, or patchy hair loss, which suggests a different cause
• Hair loss with scalp redness, scaling, itching, or pain
• Hair loss along with other symptoms such as fatigue, weight changes, or irregular periods, which may point to a hormonal or other medical condition

Related Topics

Frequently Asked Questions

References

1. American Academy of Dermatology Association. Hair loss: Diagnosis and treatment.
2. Mayo Clinic. Hair loss — Symptoms and causes.
3. MedlinePlus, U.S. National Library of Medicine. Male pattern baldness.
4. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Hair loss (alopecia areata and other types).