Hair & Scalp

Hair loss: What's normal, and when to be concerned

Diane S. Berson, MD is a Board Certified Dermatologist, an Associate Professor of Dermatology at Weill Medical College of Cornell University, and an Assistant Attending Dermatologist at the New York-Presbyterian Hospital. She has a private dermatology practice in New York City. Widely regarded as one of the leading dermatologists in the United States, Dr. Berson is frequently featured in national print, broadcast, and online publications.


While washing your hair, do you sometimes stop and wonder if so much of it should be going down the drain? We do. So, given our love of ferreting out information, we went in search of some answers. Our top resource was Diane Berson, MD, a leading dermatologist and national hair loss expert.

Ayla: You’ve been a highly regarded dermatologist for a long time, and you’re particularly known for your ability to treat scalp conditions and hair loss. Do you find that you’re seeing more patients with hair loss now than in previous years? 

DR. BERSON: I do find a large percentage of my patient population asking me about scalp conditions and hair loss. It’s partly because I specialize in adult acne treatment, and I often see hair thinning along with acne. But in general, I hear more complaints about hair thinning from women these days for three specific reasons:

1. More women are living many years past menopause, through their 80s and 90s. More women are working into later years as well. Menopause sets in at around age 50, and hair thinning tends to occur at that point, which means there’s a fair bit of time for postmenopausal women to struggle with it.

2. Hair loss used to be a taboo subject, and there weren’t that many ways for women to address it until quite recently. So patients may not have presented with it – they might have just lived with it.

3. Finally, there’s the hormonal/stress issue, which is a big one, because women are balancing more today than they used to. They are often managing a career and caring for kids, and now they’re caring for their aging parents, too, since those parents are living longer. So I’m seeing more conditions related to the hormones that are released with higher stress levels — including acne breakouts and hair loss.


Ayla: How much hair loss is “normal”? We hear “100 hairs a day” a lot.

DR. BERSON: That’s exactly it, 100 hairs a day.  You might notice hairs coming out when you’re brushing your hair, or you might see hair you’ve shed on your shoulders. That’s normal, because there are three stages in the life cycle of your hair:

- During the anagen phase (2-7 years), your hair is growing
- During the catagen phase (2-3 weeks), that growth stops
- During the telogen phase (3 months), the hair follicle is resting and your hair falls out

Normally, you have a lot of hair going through each stage at any given time.

To determine if a patient is experiencing more than that, I always ask:

- Do you have clumps of hair coming out in your hands?
- Do you see lots of hair in the drain when you shower?
- Do you see lots of hair on the pillow when you wake up?
- Are you noticing more hair loss than usual?
- Does your ponytail feel thinner? (This is commonly noticed due to hair loss, but also due to the hair strands themselves becoming thinner. This is caused by miniaturization of the hair follicles.)

If the answer to any of those questions is “yes,” it’s worth doing some investigation with a dermatologist.


Ayla: What’s the best way to find a dermatologist who specializes in scalp and hair health?

DR. BERSON: Any board certified dermatologist should be an expert at treating skin, nails, and hair, but obviously there are those who might have more of an interest in treating hair loss. If the one you contact doesn’t — for example, if they specialize primarily in skin cancer treatment — they might be able to recommend someone else.


About Dr. Berson:

Diane S. Berson, MD, is an Associate Professor of Dermatology at Weill Medical College of Cornell University and an Assistant Attending Dermatologist at the New York-Presbyterian Hospital. She has a private dermatology practice in NYC and volunteers at the NY Presbyterian Hospital Department of Dermatology, where she teaches medical students and residents. Dr. Berson has been quoted in the Wall Street Journal and the New York Times, and many magazines including Allure, Town and Country, W, and More. She has also been interviewed often in the media, including NBC’s Today Show, ABC World News Tonight, and CNN Headline News. She lectures regularly at national dermatology conferences and is on the editorial boards of Practical Dermatology, Journal of Drugs in Dermatology and Dermatologic Surgery. Read more about Dr. Berson’s impressive background here.


Any topic discussed in this article is not intended as medical advice. If you have a medical concern, please check with your doctor.

You May Also like

All About Skin

Skincare product pilling: why it happens and what to do

We couldn't think of a better person than Dr. Pedro Catalá to expound on the topic of skincare and makeup product pilling, which is quite common, quite annoying, and quite the mystery to most people except for skincare product formulators. 
Inside Our Brands

Hyperpigmentation: how marine ingredients can help

Hyperpigmentation is one of those skin conditions that increasing numbers of us struggle with, and it can be downright diabolical in many ways.
All About Skin

Marie Veronique on Soothing B3, niacinamide, and hyaluronic acid

Niacinamide: long ignored, soon to become the cool kid? Marie Veronique chats with Dara about why that might be — and bashes a TikTok myth about hyaluronic acid at the same time.