Abdominal hair includes hair growing anywhere between the upper edge of the pubic hair and the lower edge of the pecs. This type of hair growth occurs in 86% of all men but varies widely by race, with over 75% of Asian men having ab hair compared to 90% of white men.
Native American 82%
Growth of abdominal hair during puberty and early adulthood usually spreads upwards from the pubic area to the belly button, then outward from the belly button. Because of these two different directions in spreading, we can classify abdominal hair growth in two different ways – how high up the hair rises on the abdomen and the overall spread onto the abdomen (or pattern).
Extent of hair growth upwards (rise)
Rise refers to how far up the abdomen the hair grows.
Bare – No ab hair rising from the pubic hair.
14% of men (most common in Asian and Hispanic men)
Low Rise – Ab hair rises above the pubic hair but does not rise all the way to the belly button.
8% of men (most frequent in Black/African and Asian men)
Belly-Rise – Hair rises as far as the belly button and no further.
18% of men (most common in Native American men)
Mid-Rise – Ab hair rises above the belly button, but does not reach all the way to the lower chest.
28% of men (more common in European/white men)
High-Rise – Ab hair that rises all the way up to the base of the chest.
32% of men (most common in European/white men)
Extent of hair growth outwards (Shape/Pattern)
Although there are varying classifications used by researchers[i], we will classify shapes or patterns as follows:
Sagittal (line) – a single thin trail or line of hair leading up the middle of the abs from the pubic area with little to no spread.
Parallel – the hair spreads equally outward from top to bottom and does not taper to a point at the top.
Tapered – the hair spreads outward more around the belly button and/or pubic area and tapers to a point or line near the top.
Dispersed (rug-like) – hair spreads over the abdomen in a rug-like fashion.
We will review hair patterns on the abs by looking at the various shapes and then break down those patterns to how high the hair rises. We will begin first with men that have bare abs.
Some men have no abdominal hair at all. In other words, no hair rises above the pubic hair line. Having bare abs varies considerably by race with nearly one-fourth of Asian and Hispanic men having no abdominal hair compared to less than 10% of White/European men.
Native American 18%
SAGITTAL (LINE) PATTERN
Sagittal hair growth occurs along the sagittal line of the abdomen directly above and below the belly button. This is often the first stage of ab hair growth at puberty. During puberty, a line of hair begins to extend from the groin upward toward the belly button. Some call this a “happy trail” or other various nicknames. In men with other types of abdominal hair growth patterns, they often pass through this “sagittal” pattern early on before the hair starts spreading. In addition, the sagittal area will almost always be the most densely haired area on the abdomen.
TAPERED AB HAIR
Tapered ab hair patterns all come to a point at the top. There are three slight variances - triangular (left), wedge-shaped (middle), and vase-shaped. Two look similar above the waistline. It’s only below the waistline that they appear different.
The first is triangular. In this pattern the hair below the waistline spreads out and meshes with the outer edges of the pubic hair, then continues to taper to a point as it rises (forming a triangular shape overall). This is almost always the main shape of the tapered pattern for men with low-rise or belly-rise hair patterns.
The second is wedge-shaped. In this pattern the hair below the waistline narrows as it approaches the pubic hair. In some men, ab hair may not join up with the pubic hair. This creates a wedge or boat-like shape.
The third is the “tapered vase,” which again is usually only seen in mid-rise and high-rise patterns. In this pattern the shape is similar to a wedge shape around and below the belly button, but it tapers quickly to a sagittal line above the belly button. This is almost a mix between sagittal and tapered patterns.
For some, the differences between these patterns are minimal. Some will have finer hairs growing in a triangular pattern, with thicker, courser hair concentrated in the wedge shape pattern or along the sagittal line towards the top. Because of this overlap, we have placed these hair patterns in the same category.
PARALLEL AB HAIR
Parallel hair patterns occur when the width of the hair from top to bottom stays about the same without spreading onto the entire abdomen. This was the least common pattern. The four different “rises” or extents of hair growth are shown below.
DISPERSED (RUG-LIKE) PATTERNS
The dispersed hair patterns occur when the abdominal hair doesn’t really have a shape. It tends to spread across the majority of the abdomen in a rug-like fashion toward the side of the abs rather than staying more in the midline.
UNIQUE AB HAIR PATTERNS
A few men may not fit nicely into one of the above patterns. For some, they may combine different hair patterns – most often a combination of parallel and tapered and/or sagittal (line).
For others, they may have hair patterns that are more unique and create multiple tapered shapes. Some men have one pattern of hair on the upper abs and another pattern on the lower abs. A few of these possibilities have been noted in other studies[ii]. Examples are shown below:
Some men have bald patches within the main area of abdominal hair growth. These often occur because areas of the abdominals (especially along the midline near the belly button) can be less sensitive to DHT and subsequently have less hair growth. Bald spots occurred in 37% of men surveyed.
Having bald spots in the ab hair varied dramatically in our survey depending on ethnicity. It occurred in the majority of Native American (61%) and Indian/Pakistani (57%) men but only 35-39% of the time in Asian, Black/African, and Hispanic men. White/European men were the least likely to have bald patches at 24%.
The most common area for no hair growth was around the belly button. This occurred in 15% of men overall. Having bald patches in other areas such as above the belly button, below the belly button, as a ring at the top of the chest, or a strip of bald skin separating the ab hair into an upper portion and lower portion occurred less frequently (4-5%).
Obviously, the higher your abdominal hair spreads the more area there is for bald patches to occur. Only 0.5% of men with low-rise ab hair had bald patches, compared to 2% of men with belly button high hair. This number increased to 11% of men with mid-rise ab hair and 18% of men with hair that rose all the way to the lower chest.
Bald patches were most common in men who had a dispersed or rug-like abdominal hair pattern – occurring in 12% of these men. Other hair patterns including Sagittal (line), Parallel, and Tapered patterns only had bald spots 4-6% of the time.
Bald Patches Surrounding the Belly Button
This was the most common area for bald patches to occur, usually happening in around 20% of men with hair growth this high. This could be anything from a small ring with no hair to a larger area in men with dispersed patterns. These occurred most frequently in Hispanic (21%) and Indian/Pakistani (18%) men and the least in Native Americans (9%) and White/European (12%) men.
Bald Patches Above the Belly Button
As with most bald patches, these are right on the midline going up the abs. However, rather than being around the belly button, they tend to be just above the belly button. These occur in about 4% of men overall with up to 8% of Black/African men having this pattern . Only 2% of White/ European men have these patches.
Bald Patches Below the Belly Button
These patches also occur along the midline, but these fall below the belly button. These can occur in men with lower abdominal hair patterns, as well as men with higher ab hair patterns and can be either large or small. This occurs in about 5% of men being most common in Native Americans (13%) and least common in Hispanic (0%) and White/European (2%) men.
Bald Patches at the Base of the Pecs
This occurs only in high abdominal ab hair patterns where the hair reaches the lower pecs, but the area in the midline at the top is bald. This occurs in 5% of men with Indian/Pakistani men having this bald spot more than other ethnic groups.
Bald strips oftentimes form around the belly button and divide hair above and below the belly button into two separate fields of hair. This occurs in about 5% of men, but is most common in Indian/Pakistani men (8%) and least in Native American men (0%).
Below are examples of bald patches separated by hair pattern type.
Almost half of all men have abdominal hair patches that grow outside of the main field of hair. This usually occurs in small patches either on the sides of the lower abs or upper abs. It can occur on only one side or both sides. These men have patches of skin that are more sensitive to DHT than other skin outside the ab hair field. For some men these patches may be covered in hair that is as dense and dark as their other abdominal hair, while others may only have a few hairs that are darker but aren’t as course or thick as the hair that covers the rest of their abdomen.
Our survey found that 46% of men had abdominal hair patches. This varies between ethnic groups occurring in one-third of Hispanic (33%) and White/European men (34%), half the time in Asian (48%) and Black/African men (51%), and in two-thirds of Native Americans (66%) and Indian/Pakistani men (66%).
Having hair patches often depended on the type of hair pattern men had. For example, 54% of men with a dispersed (rug-like) hair pattern were most likely to have patches growing outside of the main hair area. Men with a sagittal pattern of ab hair had patches only 35% of the time. While men with parallel or tapered hair patterns had hair patches 48-49% of the time.
Having hair patches also increased significantly with how far up the ab hair grew. For example, men who have hair only growing to the belly button or below had hair patches 31-32% of the time. Men who had a mid-rise hair pattern above the belly button had hair patches 47% of the time, while men who had ab hair that grew all the way up to the chest had hair patches 56% of the time.
Upper Bald Spot on One Side
This can occur in about 6% of men overall. The patch is on either the right side or the left side of the upper ab. It may be slightly lower than shown in this picture. This occurs in 7-9% of most men with the exception in White/European men where it only occcured in 4%.
Upper Bald Spots on Both Sides
These type of patches occur in about 14% of men overall. This occurs when hair grows in two separate patches, one on either side of the upper abs. This varies widely between ethnic groups with 38% of White/European men having these patches and only 6-7% of Asian and Hispanic men having these patches.
Lower Bald Spot on One Side
This type of patch occurs on one side of the lower abs. The patch may be below or level with the belly button. This occurs in about 6% of men, being most common in Black/African men at 14% followed by Asian and Indian/Pakistani men at 10%. It is less common in Native American and White/European men (both 3%).
Lower Bald Spots on Both Sides
These types of patches are the most common and occur in 20% of men overall. Patches are located either about level with the belly button or lower. This occurs most commonly in Indian/Pakistani (28%) and Asian (23%) men. This was reported in 12-17% of men in other ethnic groups.
There are multiple variations of ab hair patterns with hair patches. The following pages are organized by Sagittal, Parallel, Tapered, and Dispersed then low to high risk within each pattern.
[i] Setty LR, J Nat Med Assoc, Varieties of the Acuminate abdominal hair pattern in white males; (58)3, May 1966, 191-3. & Setty LR, J of Nat Med Assoc, Varieties of the Quadrangular abdominal hair pattern in white males; (59)1, Jan 1967, 45-7.
[ii] (https://en.wikipedia.org/wiki/Abdominal_hair - 10/4/2016)
All images on this page are original design