What Are the Four Types of Hair Loss? A Dermatologist Explains
Professor Caitriona Ryan broke down the four main types of hair loss on Newstalk's Pat Kenny Show, explaining why identifying the right type matters before starting any treatment.
There are four main types of hair loss: male and female pattern hair loss, alopecia areata, telogen effluvium, and scarring alopecia. Each has a different cause, from genetics to autoimmune activity to physical stress, and the right treatment depends entirely on which type you have.
What Is Male and Female Pattern Hair Loss?
The most common form, affecting around half of men by age 50, and also seen in women. It's highly genetic, with over 70 genes involved, and can be inherited from either side of the family.
"The hair follicle is more sensitive to certain derivatives of testosterone floating around the body. The hair is first miniaturising to skinny hairs, and they involute, or go away. Once there's no hole there, you can't get that hair back."
It's progressive, so early treatment matters. Options include minoxidil (topical or oral), finasteride or dutasteride for men, spironolactone for women, and PRP (platelet rich plasma) injections, available in the Cosmetic Suite at the Institute of Dermatologists, as an adjunct. Hair transplants can be effective but require ongoing medication to retain the result.
What Is Alopecia Areata?
An autoimmune condition where the immune system attacks the hair follicles, causing round or oval patches of hair loss on the scalp, and in some cases the eyebrows, eyelashes or body. It can affect children and adults alike. Read our full guide to alopecia areata for causes and treatment options.
What Is Telogen Effluvium?
Often called stress-induced hair loss, and more common in women. It follows a physical or psychological stressor, illness, rapid weight loss, or a major hormonal shift such as pregnancy, and shows up as shedding roughly three months later rather than straight away.
"That stress triggers hairs to go into a resting phase, and you see them fall out about three months later... it always grows back." - Professor Caitriona Ryan
The reassuring news is that this type resolves on its own, though it can take time and feel alarming while it's happening.
What Is Scarring Alopecia?
A rarer, progressive form where inflammation permanently damages the hair follicle. Because the damage cannot be reversed once it happens, early dermatologist input is important to slow or stop progression.
Can Hair Loss From Chemotherapy Grow Back?
In most cases, yes, though certain chemotherapy drug classes can cause more lasting hair loss. Professor Ryan has noted that for many patients, losing their hair during treatment can be more emotionally difficult than the diagnosis itself.
Frequently Asked Questions
What's the difference between alopecia areata and pattern hair loss?
Alopecia areata is autoimmune and causes patchy loss at any age. Pattern hair loss is genetic and causes gradual, progressive thinning.
Does stress actually cause hair loss?
Yes, but only in the form of telogen effluvium. It doesn't cause or speed up genetic pattern hair loss.
Can hair transplants fix any type of hair loss?
Transplants are generally used for pattern hair loss and require ongoing medication afterwards to protect the result. They aren't typically used for alopecia areata or telogen effluvium, which can resolve or respond to other treatments.
When should I see a dermatologist about hair loss?
Sooner rather than later, especially for pattern hair loss or scarring alopecia, since both are progressive and easier to manage early.
Source: Professor Caitriona Ryan discussed hair loss on The Pat Kenny Show, Newstalk.
