Addressing the Root Cause of Hair Loss is Key to Successful Treatment
Leading international hair loss experts aim to educate men and women about most common causes, treatments of hair loss and importance of proper evaluation
CHICAGO – August 11, 2026. While hair loss is an extremely common condition that affects countless men and women alike around the world, unraveling the type of hair loss is an important first step in determining the best course of treatment. Whether it takes the form of a receding hairline, a widening part, or sudden shedding, hair loss presents differently in men and women and typically falls into three common clinical patterns.
To help people understand the most common root causes of hair loss, the International Society of Hair Restoration Surgery (ISHRS) outlines the symptoms of androgenetic alopecia, telogen effluvium, and alopecia areata, treatments for each type of hair loss, and signs of hair loss that people should not ignore.
“Certain types of hair loss have a strong genetic component that often runs in families, but hair loss can also be triggered by factors such as an illness, stress, nutritional deficiency, rapid weight loss, or an immune-system deficiency,” said Conradin von Albertini, MD, FISHRS, president of the ISHRS. “That’s why it is important to seek a proper evaluation by a hair restoration physician who is trained to diagnose and treat all different forms of hair loss.”
Androgenetic Alopecia (AGA)
Also known as patterned hair loss, androgenetic alopecia is the most common form of hair loss in men and women. However, the symptoms of androgenetic alopecia appear different by gender.
Men – Affecting more than 50% of men by age 50 and rising to around 80% by age 70, androgenetic alopecia typically causes gradual recession at the hairline and thinning at the crown. Male pattern hair loss generally begins after puberty and is often noticed in the 20s to 40s. Driven by genetics and sensitivity of hair follicles to DHT (a hormone derived from testosterone), this type of hair loss is marked by hairs that become progressively finer over time rather than suddenly falling out in large amounts.
The main treatment options are topical and oral minoxidil, finasteride or dutasteride, PRP, and low-level laser therapy (LLLT). When hair loss is stable and the donor area is strong, hair transplantation – a natural-looking, permanent solution for hair loss that has been continually refined – can be very effective.
Men should seek an evaluation with a hair restoration physician if the hairline recession or crown thinning is visibly progressing over six to 12 months, or if heavy shedding lasts longer than three months. Delaying evaluation has consequences, as continued thinning can become more extensive and permanent and there may be less donor hair available for a future hair transplant.
Women – Female pattern hair loss affects about 12% of women aged 20 to 29, increasing to approximately 40-50% by age 70. While hair loss can develop at any adult age, it commonly becomes more noticeable in the 30s to 50s. Hair loss usually appears as a widening part and thinning over the top of the scalp, while the frontal hairline is often unaffected. This common form of hair loss is linked to genetic factors, but it can be triggered by hormonal changes – especially around menopause. PMOS/PCOS can also trigger female pattern hair loss, particularly when thinning occurs with irregular cycles, acne, unwanted hair growth, and weight gain.
Minoxidil is the main treatment and select women may also benefit from anti-androgens or hormonal treatment. Hair transplantation can be considered when the patient is stable and the donor area is suitable. In women with PMOS/PCOS-related hair loss, managing the hormonal aspects with anti-androgens or birth control pills and metabolic aspects with weight, diet, exercise, and metformin is also important.
Women should seek an evaluation if a widening part or scalp visibility persists for several months, particularly with irregular cycles, acne, unwanted hair growth, weight gain, or fertility concerns. As is the case with men, delaying a proper evaluation can result in more extensive and permanent thinning with less donor hair available for a future hair transplant.
Telogen Effluvium (TE)
Telogen effluvium, commonly referred to as temporary diffuse shedding, is a very common form of sudden shedding that affects both men and women and can occur at any age. It can be triggered by a number of factors – illness, surgery, childbirth, severe stress, thyroid problems, crash diets, rapid weight loss, and nutritional deficiencies such as low iron, anemia, vitamin D deficiency, or low zinc.
The classic sign of telogen effluvium is increased shedding from all over the scalp, usually beginning two to three months following a trigger. The ponytail or overall hair volume feels thinner, but the scalp and hair shafts usually look normal.
“With the increasing popularity of GLP-1s, patients may experience temporary hair shedding that can be triggered from nutritional and metabolic stress as a result of weight loss that is fast or when food intake becomes inadequate,” said Dr. von Albertini. “It is important that patients taking these medications report any hair loss-related side effects to their physician and to ensure their diet is enriched with adequate protein, calories, iron, and micronutrients.”
Dr. von Albertini added that the good news is telogen effluvium is usually temporary and fully reversible, with the focus on finding and correcting the trigger. This includes treating thyroid disease, correcting iron deficiency or anemia, improving nutrition, managing stress, and ensuring safe, well-supported weight loss in people using GLP-1 medication. While hair transplantation is not indicated for this type of temporary hair loss, short-term minoxidil may sometimes be used to support regrowth.
Alopecia Areata
Marked by visible spots of patchy hair loss, alopecia areata is an autoimmune condition that affects men and women equally and can begin at any age but often starts in childhood or young adulthood. The condition causes sudden, smooth, round bald patches on the scalp, eyebrows, beard, or other body-hair areas, and the skin usually looks normal. A person’s average lifetime risk of developing alopecia areata is approximately 2%.
Treatments for alopecia areata include steroid creams or injections into the affected areas, and more extensive cases may require immune-modulating tablets or newer targeted therapies. Hair transplantation is generally not used when autoimmune activity is ongoing. Delaying an evaluation when signs of this condition are noticeable can make this type of hair loss harder to manage.
In addition to the three most common forms of hair loss, Dr. von Albertini added that there are a few additional causes that should be kept in mind, including:
- Traction Alopecia – Hair loss caused by ongoing pulling from tight ponytails, braids, buns, extensions, weaves, or dreadlocks. The hairline and temples are commonly affected by this type of hair loss, and it can begin at any age – especially after years of high-tension styling.
- Primary Scarring Alopecia – These are inflammatory conditions in which follicles are destroyed and replaced by scar tissue. They are seen most often in middle-aged and older adults, particularly women.
- Drug-induced Hair Loss – This may occur as a side effect of medication, including chemotherapy. It needs careful evaluation of the timing, the medication involved, and other possible causes. While chemotherapy is a primary cause, other medications may cause a delayed, telogen effluvium shedding pattern after a new medication or dose change.
- Eyebrow Loss – While over-plucking, waxing, threading, or repeated cosmetic removal are common causes of eyebrow loss, this type of hair loss can also offer important clues about the underlying cause. If eyebrow loss is a result of an aesthetic procedure, the repeated trauma can damage hair follicles especially in the outer brows. Treatments for this type of eyebrow loss can include topical minoxidil or an eyebrow transplant to restore density and shape. Dr. von Albertini noted that other contributing factors of eyebrow hair loss include thyroid-related hair loss, alopecia areata, and frontal fibrosing alopecia.
Despite the rising popularity of products and supplements marketed to treat hair loss, Dr. von Albertini advised that consumers should be cautious about using them. For example, unregulated “DHT-blocker” supplements promise dramatic regrowth without strong evidence, and they can delay proven treatment. Extreme detoxes and crash diets can trigger telogen effluvium through rapid weight loss and poor nutrition. Unmonitored hormone, steroid, or “hormone-balancing” products can worsen hair loss or complicate proper medical care.
“One key sign of hair loss that people should not ignore is a persistent change in hair pattern or density,” said Dr. von Albertini. “Seeking a proper medical assessment by a physician trained in the art and science of hair restoration in the earliest stages of hair loss is critical to successful treatment outcomes.”