Hair Shedding: Everything You Need To Know

Most people with healthy hair have approximately 100,000 hairs on their head. 90% of these hairs are actively growing [1]. The remaining 10% are resting (known as telogen) or shedding (known as exogen).

Hair shedding is a natural part of the hair growth cycle. But if too many hairs start to shed, it can be a cause for concern. So when does normal hair shedding become excessive — and what can you do about it? In this article, you’ll learn:

• how to recognise excessive hair shedding
• what causes hair shedding
• how to stop hair shedding if you’re losing too much hair.

What is hair shedding and how much is normal?

Hair shedding is the process of removing old hairs to make way for new, healthy hairs. If you have a normal rate of hair shedding, you may lose up to 100 hairs a day. This is an accepted rate of hair loss; if you’re losing less than this, you don’t need to worry.

Photo showing 100 hairs from a person with short hair (left) and longer hair (right).

Excessive hair shedding happens when you lose more than 100 hairs a day. You’re likely to notice more hair loss in the shower, on your pillow, or on your hairbrush.

What causes hair shedding?

For most people, hair shedding is caused by your natural hair growth cycle. But if your hair loss is excessive, there’s usually an underlying cause. These include:

• Hair loss conditions — the most common cause of excessive hair loss is androgenetic alopecia, also known as male pattern baldness or female pattern hair loss
• Your mental health — anxiety and depression are known triggers for stress-related hair loss
• Medication — medications that cause hair loss include the pill, antidepressants, and chemotherapy drugs
• Health conditions — many autoimmune disorders cause hair loss, and there’s now evidence also linking hair loss with Covid
• Hair loss treatments — Finasteride shedding and Minoxidil shedding are common temporary side effects of these solutions
• Seasonal hair shedding — some people see more hair shedding in summer [2].

There are many reasons why your hair may be falling out. If you’re not sure what’s causing your excessive shedding, get a diagnosis from a professional trichologist.

Why does hair shedding happen?

There are three major types of hair shedding:

• Exogen — normal hair shedding that occurs as part of the hair growth cycle
• Anagen effluvium — shedding of growth phase hairs
• Telogen effluvium — shedding of resting phase hairs.

While all hair shedding looks similar to the naked eye, researchers have found differences in hair anatomy depending on which type of hair shedding you have [3]. In contrast to telogen and anagen phase hairs, cells in the follicle base of exogen hairs separate cleanly from those holding the hair in place.

The mechanism that causes normal hair shedding isn’t conclusively known. Some researchers suggest that new hairs push old hairs out of the follicle to make way for new growth. But more recent research suggests cells of the hair root actually send signals to the follicle to stimulate exogen [3].

In telogen effluvium, the body enters the telogen phase prematurely, causing more hair to shed at once. This is usually triggered by trauma, stress, illness, or hormonal changes [5]. In anagen effluvium, shedding is caused by extreme damage to the hair shaft, causing it to break off [1]. Anagen effluvium is usually associated with chemotherapy-related hair loss. Many chemotherapy patients have complete hair loss within 2-3 months of starting treatment [1, 4].

Hair shedding vs hair loss: is there a difference?

The terms hair shedding and hair loss are often used interchangeably. But they usually refer to slightly different processes.

Hair shedding can refer to normal hair fall, as well as hair loss caused by medication, hair loss treatments, and seasonal changes. It often means there’s a chance the hair will regrow by itself.

Hair loss, meanwhile, usually refers to longer term conditions (such as pattern baldness and alopecia areata) that can be permanent. Hair shedding often becomes hair loss if you develop noticeable bald patches, or your hair doesn’t grow back within a few months.

How long does hair shedding last?

The longevity of your hair shedding depends on how quickly you can address the underlying cause. Telogen effluvium usually lasts less than 6 months, although if it’s caused by long-term medication or unresolved stressors, it may last longer [7]. Similarly, anagen effluvium usually lasts as long as your course of chemotherapy.

In most of these cases, hair will regrow by itself when the underlying cause of hair loss has been tackled. You can also try solutions like Minoxidil, caffeine shampoo, and vitamin E supplements for hair to stimulate growth more quickly.

If you have a permanent hair loss condition like androgenetic alopecia, hair shedding may continue until you have widespread hair loss across your scalp.

What does hair shedding look like?

Counting the number of hairs you lose in a day isn’t a practical way to measure hair shedding. The image chart below provides a visual guide to what specific amounts of hair shedding look like in a person with shoulder-length hair [6]:

Use this scale to measure your own hair loss per day.

How to perform the hair pull test

The hair pull test is another way to find out how much hair you’re losing. If you see a trichologist or doctor about your hair loss, they’ll probably perform this test on you — but you can also try it yourself.

1. Select a small clump of hairs (around 50-60) at the crown of your head and hold them with your fingers near your scalp.
2. Slowly but firmly, pull your fingers down the hair shafts.
3. If any hairs have come away, put them to one side.
4. Repeat the test three more times: once at the back of your head, once on the left side, and once on the right side.
5. Count the number of hairs that have shed (excluding broken hairs).
6. If more than 10% of the hairs in each clump have come away (approximately 5-6 hairs per pull), you’re experiencing excessive hair shedding [8].

How to stop hair shedding

If your hair is coming out at a normal rate, there’s nothing to worry about. Accept that some hair shedding is a natural part of hair growth, and look forward to the fresh new hair that will grow in their place.

But if you’re losing too much hair, it’s essential that you take steps to stop shedding and stimulate new hair growth. Here’s what you can do.

1. Seek professional advice

If you’re not sure why your hair is falling out, it’s best to speak to a professional. Whether it’s your GP or a hair loss specialist, they can help rule out certain causes and help you create a treatment plan.

2. Tackle the underlying cause

When you know what’s causing your hair loss, take steps to address it. If your hair loss is rooted in anxiety or depression, it may help for you to speak to a mental health professional. You might also have a previously undiagnosed condition which is contributing to your hair loss, in which case you can seek treatment advice from your doctor.

3. Eat well

Your diet can have a big impact on the health of your hair. Avoid fad diets, eat plenty of hair growth foods, and make sure your diet is optimised for healthy hair.

4. Exercise

Hair growth relies on good circulation to make sure your scalp and hair follicles get plenty of nutrients. Exercising regularly can improve your circulation, and it’s great for your general health, too.

5. Take care of your hair

Damaged hair becomes brittle and snaps off at the ends, making your hair look thinner. Avoid heat styling and tying your hair back too tightly, as these can damage your hair further.

Hair shedding after a hair transplant: is it normal?

Many hair transplant patients notice their hair grafts falling out after a hair transplant. This is known as shock hair loss, and it’s a normal part of the hair transplant recovery process. After a few weeks, you’ll start to see new growth in your previously thinning areas.

In some rare cases, your non-transplanted hairs may fall out after a hair transplant procedure. This is a reaction to the surgery, and is more likely to happen if your surgeon is less skilled or experienced. Fortunately, this type of hair loss is almost always temporary; your hair will regrow after a few months.

If you’re worried about how much hair you’re losing, or you’re not sure what’s causing your hair shedding, book a free consultation with the Wimpole Clinic. We can help diagnose your hair loss and create a treatment plan designed specifically for you.

Sources:

1. Anagen Effluvium
2. Seasonality of hair shedding in healthy women complaining of hair loss
3. Exogen, Shedding Phase of the Hair Growth Cycle: Characterization of a Mouse Model
4. A Hospital-based Study to Determine Causes of Diffuse Hair Loss in Women
5. Telogen Effluvium
6. The Hair Shedding Visual Scale: A Quick Tool to Assess Hair Loss in Women
7. Telogen Effluvium: A Review
8. Hair pull test: Evidence-based update and revision of guidelines