Vellus hair is peach fuzz-like type of hair. It serves a different purpose than other hairs on your body. It helps with regulating body temperature and evaporating sweat.

Vellus hair refers to the thin, tiny hairs on your body. You’ll find them if you look closely at seemingly hairless areas, such as your ear lobes or face. It’s also sometimes referred to as peach fuzz or baby hair.

You probably don’t give a second thought to these hairs or understand how they’re different from the other hairs on your body. But vellus hair does serve a useful purpose.

Here’s what to know.

Vellus hair is short, fine hair that starts to develop in childhood. If you look closely, you can see it on many areas of the body, including your face, neck, and ear lobes. Vellus hair helps with regulating your body temperature and evaporating sweat.

Terminal hair is thicker, longer, and darker, which makes it more noticeable. It’s the type of hair that, once you hit puberty, will start to grow in areas like the pubic region and underarms. It will also show up on your arms and legs. Terminal hair also helps with regulating body temperature as well as protecting your body from sun and germs.

Neither type of hair grows in areas where there are no hair follicles, like the palms of your hands, soles of your feet, or lips.

Body hair undergoes various changes as you become older. In many cases, vellus hair is replaced with thicker hair in certain areas of your body during puberty. When this transition occurs, vellus hairs become terminal hairs.

For example, prior to puberty, a young man may have vellus hair on his chin, face, and above his upper lip. As puberty begins, these hairs change to terminal hair and become longer and stronger. This is when males develop facial hair like a mustache or beard.

Other areas on your body where vellus hair becomes terminal hair include your:

  • chest
  • abdomen
  • legs
  • arms
  • armpits
  • pubic area
  • tops of feet

This changeover results from an increased production of a hormone called androgen. Androgen is natural to males and females, but males have a higher level. Therefore, men typically have more terminal hairs than women.

However, later in life, people who lose terminal hair often still have vellus hair. For example, even if an older male has a bald spot on his head, the area still likely has fine patches of vellus hair.

The amount of vellus hair on an adult varies from person to person.

Genetics, aging, and hormonal changes can all impact the amount of vellus hairs you may have. Additionally, some people have more pigmented vellus hairs, making the hairs more visible and noticeable compared to other people with less pigmented hairs.

Some conditions spur vellus hair growth. It’s important to speak with your doctor if you notice an increase in vellus hairs on your body.

Cushing’s syndrome

Cushing’s syndrome is a condition in which your body produces too much of the hormone cortisol. Symptoms may include:

  • weight gain
  • purple stretch marks
  • acne
  • slow-healing wounds

For some, this hormonal imbalance can also trigger an increase of vellus hairs on their face and body.

Anorexia nervosa

Someone who has anorexia nervosa, a type of eating disorder, may also have a higher percentage of vellus hair.

Those living with anorexia nervosa restrict their food intake due to a fear of weight gain. As a result, they may not receive enough nutrients from their diet. And nutrient deficiency can interfere with their body’s ability to change vellus hair to terminal hair.

Alopecia

Research shows that people who have alopecia, the medical term for balding, may experience an increase in vellus hair growth.

Vellus hair is common with a form of alopecia commonly referred to as male pattern baldness. This type of hair loss occurs when a hormone called DHT damages hair follicles. As a result of this damage, terminal hairs thin and vellus hairs appear.

It’s normal for vellus hairs to grow all over the body. The number of tiny hairs you have on your body may vary throughout your life.

Although these hairs are common, don’t hesitate to speak with your doctor if you notice an increase in vellus hairs. This can be a sign of a health concern that requires medical attention.