Is Your Hair Fine or Thin? Here's How to Tell the Difference

If you thought figuring out your skin type was tricky, just wait until you try to narrow down your hair type. There are oodles of charts, graphs and quizzes out there, and even if you spend a good chunk of time perusing those, you can still be stumped. But there’s one debate in particular that can be a real mystery: deciding if you have fine hair vs. thin hair (and how to care for your hair type accordingly).

To add to the confusion, the terms are sometimes used as one and the same. “In the dermatology world, we use the words fine hair and thin hair interchangeably,” says Helena Kuhn, MD, assistant professor of dermatology at Brown University. “Different ethnicities have a different size and shape of the hair follicle, accounting for the different hair types seen throughout various populations.”

So is there really even a difference between the two? Ahead, Dr. Kuhn, board-certified dermatologist Nazanin Saedi, and celebrity hairstylist Andrew Fitzsimons explain the difference between fine hair vs. thin hair, plus the best ways to care for each hair type.

What Is Fine Hair?

“Fine hair means that the actual diameter of your hair is thin,” explains Dr. Saedi. So, what exactly does that translate to for your strands? “Fine or thin hair is the result of a small and narrow hair follicle that creates a thin hair shaft, leading to hair that looks and feels thin and in general does not have much volume,” Dr. Kuhn says. “Hair follicle shape and size is a genetically determined trait and we can’t do much to change the thickness of the hair shaft, unfortunately.”

What Is Thin Hair?

“Thin hair refers to the density—i.e. the number of strands—of the hair in a given area on your scalp,” Dr. Saedi says. “So, it is the amount of hair on your scalp.” To help you differentiate between fine hair vs. thin hair, Dr. Saedi explains that you can have fine, hair but have a high density of hair to make it look thicker.

Thin Hair vs. Thinning Hair

Since thinning hair refers to the loss of hair density on the scalp, this means existing hair follicles are becoming smaller, resulting in finer and sometimes shorter hair, and less hair overall.

“Thinning hair is when you are losing hair and the density of hair on your scalp is getting less,” Dr. Saedi says. “Patients come who have thick hair but complain about it thinning—it usually is not the individual hairs becoming thinner but losing the density, so there’s fewer hairs on the scalp.” 

How to Tell If Your Hair Is Thinning

One telltale sign of thinning hair is noticing your part has gotten wider and increased in size, or if you can wrap around your hair tie more times when you put it in a ponytail, says Dr. Saedi.

“People with thinning hair start to notice a change from their baseline hair type, for example, that their ponytail is a lot thinner, or that they have a lot less hair when they are shampooing,” Dr. Kuhn says. “The scalp also becomes more visible as the hair thinning occurs, which is often how patients begin to notice their hair thinning. Some people also notice an uptick in shedding. Shedding up to 150 hairs a day is normal, but when it becomes excessive, prolonged shedding is concerning.”

Thinning hair is most often due to androgenetic alopecia, which is female pattern hair loss or male pattern hair loss. This loss is primarily due to age and genetics, and it’s difficult to reduce your risk. Hair loss can be inherited from both sides of the family. “There is no cure yet, unfortunately, but with early and consistent treatment it can be reversed,” Dr. Kuhn says. “Thinning can also result from chronic shedding, which in the medical world we refer to as ‘telogen effluvium.’ There are a variety of causes for telogen effluvium, which is generally understood as hair shedding in response to a stressor.” 

With telogen effluvium, Dr. Kuhn explains that the actual hair shedding itself is often delayed three months after the stressor, and hair will then shed an additional three to six months. The stressor can be emotional stress (breakup, death of a loved one, severe depression or anxiety), or physical stress (like a traumatic accident or significant surgery), from rapid weight loss, medications (retinoids, beta blockers, calcium channel blockers, antidepressants, lithium), post-partum, iron deficiency, vitamin A excess, severe thyroid disease, or general anesthesia. “This type of hair loss is temporary and non-scarring, meaning once the stressor is resolved or removed, the shedding will stop and hair will regrow,” she says.

In Latinx and African-American populations, tight hairstyling can also lead to hair thinning. “This type of loss can be permanent, so these populations should seek treatment for hair loss as soon as possible,” Dr. Kuhn says. “There are also many rare causes of hair loss due to inflammatory and autoimmune disorders that I see and treat in my clinic.” If hair thinning persists, make an appointment with a dermatologist or trichologist.

Styling Fine Hair

To make the most of fine hair, it’s all about learning to work with it and style it the right way. “With fine hair, you could have really, really thick hair density-wise, so you could still definitely have layers,” says Fitzsimons. “You can have your hair more razor cut—you don't have to have it as straight across like when your hair is thinner. You want the baseline of your hair to look as thick as possible, so when your hair is fine, you can get away with more if you have a lot of it.”

“Use clarifying products and exfoliate the scalp semi-regularly to help stimulate the follicles and hair growth, and opt for shorter, more blunt cuts to give off a fuller look,” Fitzsimons says. “My Andrew Fitzsimons Body Volume line, which contains caffeine, as a range is great, especially the Blowdry Hold Spray that is applied to wet hair (prior to blow-drying) to help lift the hair from the root and build flexible volume.” 

Styling Thin Hair

There's no rule book that says you have to sport a certain style just because your hair is thin or thinning. Wear whatever style you feel suits you—but if you're in the market for a style that will create the appearance of fullness, you definitely have choices. "There are options when it comes to extensions for adding more hair or using products that will allow your hair to look fuller," says Fitzsimons. "Generally, when it comes to haircuts, if your hair is thin, the shorter your hair then the fuller it will look.” 

Many people with thinning hair use fibers or colored sprays to camouflage the scalp. “These are fine to use for special occasions or a couple times a week, but I strongly recommend not using these products daily as there is evidence that they can occlude hair follicles and worsen androgenetic alopecia,” Dr. Kuhn warns. 

Make sure to avoid heavy products on thin hair, which can weigh it down and make it even flatter. To add volume, Fitzsimons recommends cleansing the hair and scalp very well and using a lightweight conditioner. Volumizing sprays and mousses will help lift hair at the root, such as the R+Co Balloon Dry Volume Spray or the Kerastase Densifique Bodifying Mousse. 

“Use formulas with keratin building ingredients to help promote the health of the hair shaft, and similar to thin hair, be sure to exfoliate the scalp often as product buildup can weigh the hair down, whereas the goal should be to make the hair look as full as possible,” Fitzsimons says.  

The Final Takeaway

When it comes to fine hair vs. thin hair, it’s important to remember that there are differences between the two and they should be treated as such. Fine hair refers to the thickness—or diameter—of a single strand of hair. Meanwhile, thin hair refers to the actual volume—or number of—hair strands you have on your head.

All of our experts note that there are certain haircare factors to take into account when it comes to treating and styling your fine or thin hair. But our experts also agree they many people with average hair strand diameter and density think they have thin hair because of unrealistic beauty standards.

“Honestly, in haircare, only overly thick hair is ever advertised, a lot of the time to the point where it's not realistic,” Fitzsimons says. “Very, very, very few people on the planet have that amount of hair, so also it comes down to expectation. Often people will think they have to cut their hair because it appears thin. And I'll say, ‘no, your hair looks like the amount of hair that most people have.’ It's just that we're bombarded with all of these unrealistic images all of the time."