Hair

The number and quality of hairs on our heads varies as we are born with different conditions. We humans have about 100,000-160,000 hairs on our heads. In total, we have about 5 million hairs on our entire body.

Why we have hair may not be something you think about much. But the fact is that how much hair we will have is determined early in the foetal stage and is genetic.

How fast does hair grow?

Our hair grows on average 1-1.5 cm/month, i.e. 15 cm/year. A hair does not grow at the same rate all the time but has three different growth phases that form cycles. These growth phases vary with the type of hair: hair with a long growth period, such as head and beard hair, can grow longer than other types of hair.

How many hairs we lose per day is individual.

We lose about 50-100 hairs a day, sometimes we can lose a lot of hair and sometimes it doesn't grow back. This can be a case of hair loss.

A hair is made up of keratin

A hair is made up of keratin, which is exactly the same keratin used in our skin and nails. Each hair consists of dead keratinised cells in three different layers.

hair follicles

We have hair follicles or hair folicles all over our body and for each hair we have a small flap of skin that anchors each hair follicle. What we see on our scalp are the hairs.

This is how a hair follicle is structured

A hair follicle is a cavity with a secretory gland where hairs grow. Each follicle produces about 1-3 hairs, but some people can have up to 6 hairs in a follicle but this is extremely rare. The most common is for 1-2 hairs to grow. Your hairs grow in the hair pulp which is at the base of the hair follicle, this is where the cells divide and grow and produce hairs.

The lowest part of the hair shaft is surrounded by the root papilla, which connects connective tissue and blood vessels. The task of the papilla is to nourish the hair follicles, delivering hormones that regulate the growth and structure of the hair. The cell division that takes place pushes the still invisible hair upwards, once it becomes visible it is made up of fused, dead and hard cells that are our hair.

Around each hair follicle, there are sebaceous glands whose job is to act as a lubricant for the hair and hair shafts. People who get oily hair easily simply have an excess of sebum in their hair.

The hair growth cycle: active phase and resting phase

Our hair growth goes in cycles, like all cells in the body, and each hair follicle has an average of 25 life cycles. This means that a person loses hairs from the same follicle 25 times in a lifetime. A follicle produces hair between 2-6 years and then goes into hibernation for a few months. After a resting period, the root papilla disappears and the hair dies and falls off after some time. We can experience noticeable hair loss if we have growth disorders.

The life cycle of a hair can be disrupted, resulting in hair loss before the normal growth phase.

Reasons can be:

• Physical stress, surgical procedures, haemorrhage, prolonged high fever, etc.
• Seasonal changes
• Hormonal imbalance

 

Our hair follicles are surrounded by a collagen that acts as a protein to support the scalp. When our hair cycle is disrupted, it can often be due to an overproduction of collagen, which in turn causes a collagen collection to solidify around the hair follicle. As a result, the hair root becomes compressed and loses its attachment to the scalp. The impaired circulation of the scalp contributes to a lack of nutrition for the follicle, resulting in thinning hairs and weakened attachments, causing the hair to fall out.