Is my hair oily or dry?

Dear clueless,

At the root of oily or dry hair is sebum production. Sebum is your body’s natural moisturizer. It’s produced by sebaceous glands on your face, upper back, chest, and scalp. This oily, waxy substance makes its way from the scalp down each strand of hair, lubricating it and preventing it from drying out. Longer hair does tend to get dry at the ends, but lots of other factors such as hormones, hair type, and styling products also affect the condition of your hair. 

What affects the condition of your hair? 

Many factors can affect sebum production and the condition of your hair. These include: 

• Age: Younger people tend to have more active sebaceous glands. This is because they have higher levels of hormones known as androgens. 
• Hair length: Sebum comes from glands on the scalp and must travel down each hair strand to moisturize it. As such, hair tends to be drier at the ends compared to the roots. Longer hair tends to get dry, compared to shorter hair. 
• Hair type: Coarse, curly, and kinky hair tends to be drier than straight, silky hair. This is because it’s harder for sebum to travel down coil-shaped strands of hair compared to straight hair. 
• Activity level: Exercising and sweating heavily can lead to a buildup of sebum, sweat, and other debris on the scalp. 
• Genetics: Some people naturally produce more oil than others. 

What causes oily hair? 

Oily hair tends to look greasy or wet, as sebum builds up quickly. Some people also experience acne and dandruff. 

Some common causes of oily hair include: 

• Hormonal fluctuations: People often notice an increase in oil production around their period, due to changes in estrogen and progesterone levels. Polycystic ovary syndrome (PCOS) can also cause higher levels of testosterone, which increases sebum production. 
• Skin conditions: Seborrheic dermatitis on the scalp can lead to greasy hair, along with redness and flaking. 
• Scalp yeast infection: Yeast infection on the scalp can lead to moist skin and greasy skin patches. 
• Hair products: Heavy, moisturizing shampoos can weigh your hair down. Heavy pomades, hair waxes, gels, and oils can also lead to greasy hair. 

What causes dry hair?

Dry hair tends to be brittle and prone to split ends. The scalp may also be dry, irritated, or itchy. 

Some common causes of dry hair include: 

• Mechanical damage: Hair is made up of different layers. The outermost layer is called the cuticle. It’s made up of overlapping keratin cells. Combing and brushing can damage the cuticle over time, causing edges to peel off. Shampooing and scrubbing hair can also damage hair strands. 
• Chemical damage: Relaxers, bleach, and hair dye can weaken the naturally occurring bonds in your hair and damage the protective barrier of the cuticle. This causes the hair to become brittle and more prone to damage. 
• Environment: Exposure to ultraviolet (UV) radiation can cause hair to become dry and brittle. 
• Heat damage: Blow-dryers, curling irons, straighteners, and other heat tools can split the cuticle layers and weaken inner layers. 
• Malnutrition: Insufficient protein intake can lead to dry and brittle hair. 
• Hormonal imbalances: Thyroid disease can lead to dry and brittle hair. 

How can you take care of your hair? 

If you have oily hair, it’s a good idea to wash your hair more frequently. You might also consider using a clarifying shampoo regularly to remove buildup from your scalp. Between washes, dry shampoo can help keep things looking fresh. Brushing your hair regularly also distributes oils throughout your hair, preventing greasy roots.

If you have dry hair, it’s recommended to wash your hair less frequently and avoid using shampoos that contain detergents like sulfates. Using conditioner after shampooing can help to moisturize and fill in damaged areas of the cuticle. Some conditioners also contain protein-based ingredients like amino acids. These small proteins penetrate the inner layers of the hair, restoring its ability to retain moisture.

You may be familiar with the idea that if you wash your hair less often, you can “train” your hair to be less oily. Unfortunately, sebaceous glands are controlled by hormones. Therefore, oil production can’t be changed by hair washing routines. Regardless of your hair type, a strategy you can try is to shampoo your roots and condition your ends. Focusing shampoo on your roots helps to lift dirt and grime from your scalp, which is where sebum comes from. Keeping conditioner away from the scalp prevents greasy roots.  

You might also consider speaking with a dermatologist to learn more about hair health. They may be able to help you identify your hair type and offer tips on caring for your hair.  

Good luck!