Knowledge base

Hair falls out in round or oval patches while the skin usually looks normal, without flaking, redness or scarring. Hair loss occurs because the immune system temporarily attacks the hair follicles, causing hair growth to stop.

Relevance for hair and scalp
Alopecia areata can cause insecurity because it starts suddenly and is visible. In many cases, hair regrowth is possible because hair follicles remain intact.

This type of hair loss occurs in both men and women. The hair follicles are genetically more sensitive to the hormone DHT. As a result, hairs grow thinner and shorter over time, until they eventually stop growing. This process develops slowly and often follows a recognisable pattern.

Relevance for hair and scalp
Androgenetic alopecia is the most common form of hair loss and affects hair density and the overall appearance of the hair.

During chemical treatments, strong substances are used to change the colour or structure of the hair. These substances open the hair’s protective outer layer. This can make the hair drier, weaker and more fragile. The scalp can also become irritated, which may cause itching, redness or a tight feeling.

Relevance for hair and scalp
Chemical hair damage can cause hair to break more easily or appear thinner. Sometimes hair shedding increases temporarily, especially after bleaching. In most cases, the hair follicles remain intact and the hair can recover with proper care and rest.

With dandruff, the skin renews itself too quickly, causing loose skin flakes to appear in the hair or on the shoulders. This can be accompanied by itching and sometimes redness. Dandruff is not dangerous and not a disease, but it can be uncomfortable.

Relevance for hair and scalp
Dandruff mainly affects scalp comfort and the appearance of the hair, but it usually does not cause permanent hair loss.

When the roller is used, the small needles create very tiny punctures in the top layer of the skin. This process is called microneedling. It can help activate blood flow and support the skin’s natural renewal process. As a result, the skin may absorb care products more easily. The effect differs per person and depends on skin type, use and frequency.

Relevance for hair and scalp
Dermarollers are used in hair and scalp routines as a supportive tool. They are not a medical treatment and do not guarantee results.

In people who are genetically sensitive, DHT can cause hair follicles to become smaller and produce thinner hair. DHT blockers aim to support this process by making it harder for DHT to affect the hair follicle. They exist in different forms, such as shampoos, lotions and supplements, and can contain natural or synthetic substances. Their strength and effect can vary per product.

Relevance for hair and scalp
DHT blockers are often discussed in relation to hereditary hair loss, where sensitivity to DHT plays a role.

DHT belongs to the group of male hormones. It plays a role in physical changes such as body hair growth, beard growth and changes during puberty. DHT is also active in the skin and hair follicles. It works more strongly than testosterone because it binds more easily to the hair follicle.

Relevance for hair and scalp
In people who are genetically sensitive to it, DHT can influence how hair follicles function. This can play a role in hereditary hair loss.

With a dry scalp, the skin often feels tight or sensitive. Small, white flakes may appear, and itching can occur. Dryness can be caused by internal factors such as hormones or stress, as well as external factors like washing with hot water or using harsh shampoos.

Relevance for hair and scalp
A dry scalp can cause discomfort and affect how hair feels and looks, but it usually does not cause permanent hair loss.

Exfoliating shampoos often contain ingredients such as salicylic acid. These ingredients help loosen stuck flakes and deeply cleanse the scalp. Unlike regular shampoo, an exfoliating shampoo works more intensively on the scalp rather than focusing only on the hair.

Relevance for hair and scalp
Regular exfoliation can help keep the scalp clean and balanced. This may support relief from issues such as dandruff, itching, an oily scalp or blocked hair follicles. A clean scalp also allows care products to work more effectively.

The skin constantly renews itself, but dead skin cells can sometimes remain on the surface. During exfoliation, these cells are gently loosened and removed. This can be done with mild acids, such as salicylic acid, or with specially developed products. Exfoliation is done carefully and aims to keep the skin clean and fresh.

Relevance for hair and scalp
On the scalp, a build-up of dead skin cells and sebum can cause flakes, itching or blocked hair follicles. Exfoliation helps keep the scalp clean and balanced and supports a healthy environment for hair growth.

In folliculitis, a hair follicle becomes inflamed when bacteria, yeasts or other micro-organisms enter the follicle. This can happen when the skin is irritated or damaged, for example by shaving, friction, blocked pores or oily skin.

Relevance for hair and scalp
Folliculitis can cause itching, redness and small bumps around hairs. On the scalp, it can cause discomfort and temporarily affect scalp comfort. In most cases, folliculitis is treatable and not permanent.

When hair is healthy, the cuticles lie flat, helping hair retain moisture and reflect light. When damaged, hair loses moisture more easily and can feel rough or tangled. Damage can be caused by heat, chemical treatments or friction.

Relevance for hair and scalp
The condition of the cuticles affects hair strength, shine and smoothness. Proper care helps keep them intact.

Healthy hair is flexible. When gently pulled, it stretches slightly and then springs back. Hair with low elasticity may feel stiff or dry and break more easily. Heat, chemical treatments, sun exposure and nutrient shortages can reduce elasticity.

Relevance for hair and scalp
Good elasticity helps prevent hair breakage. When hair loses flexibility, it breaks more easily and can look thinner. Gentle care and proper nutrition help support elasticity.

The hair follicle extends from the upper layer of the skin down into deeper layers. New hair cells are produced at the base of the follicle, which allows hair to grow. Each hair follicle follows a fixed cycle of growth, transition and rest. Hair follicles can become less active due to factors such as stress, hormones, illness or genetic sensitivity.

Relevance for hair and scalp
Hair follicles determine how thick, strong and fast hair grows. When they function well, hair grows in a healthy way. When they become less active, hair can become thinner or fall out more easily.

Each hair follows the same cycle again and again. This cycle consists of a growth phase, a transition phase and a resting phase. Not all hairs are in the same phase at the same time. This is why hair usually looks full, even though you lose hairs every day.

Relevance for hair and scalp
The hair growth cycle determines how long hair can grow and how much hair you lose. When this cycle is disrupted, it can lead to thinner hair or hair loss.

Hair does not grow continuously, but follows a fixed cycle with three phases: growth, transition and rest. On average, scalp hair grows about 1 centimetre per month, but this can differ per person. The growth rate is mainly influenced by the length and activity of the growth phase. Factors such as age, genetics, hormones, health and lifestyle can affect how fast hair grows. Hair also grows at different speeds on different parts of the body.

Relevance for hair and scalp
Hair growth rate influences how quickly hair becomes longer, fuller or more visible after hair loss or thinning. It is therefore an important concept when setting expectations about hair growth and recovery.

The hair shaft is mainly made of keratin, the same protein found in nails. This part of the hair is not living and cannot repair itself. It consists of several layers that determine colour, strength and elasticity. Damage from heat, colouring or friction occurs in the hair shaft.

Relevance for hair and scalp
The condition of the hair shaft influences how healthy the hair looks and feels. When damaged, hair can become dry, brittle or frizzy. Further damage can be limited with gentle care.

Hairs become finer, shorter or fewer hairs grow back. This usually happens slowly and evenly across the scalp. You may notice a wider parting or less volume.

Relevance for hair and scalp
Hair thinning can have various causes, including genetics, hormonal changes or stress. Identifying the cause may help slow further thinning.

When the scalp is well hydrated, it does not feel tight or itchy and flakes or irritation are less likely to occur. Proper hydration helps support the scalp’s natural protective layer. When moisture levels are low, the scalp can become dry, sensitive and more prone to issues such as itching or redness.

Relevance for hair and scalp
A well-hydrated scalp forms a healthy base for hair growth and hair care. It helps keep the scalp balanced and supports overall hair comfort and condition.

This yeast feeds on the natural oils of the skin. In some people, Malassezia can irritate the scalp, which may lead to increased flaking. It plays a role in dandruff, but it is not the cause in everyone.

Relevance for hair and scalp
The scalp’s reaction to Malassezia can contribute to flaking and itching.

Mechanical damage occurs when hair is pulled, rubbed or put under tension. This can happen due to rough brushing, frequent combing, tight hairstyles or friction from clothing or pillows. As a result, the hair becomes weaker and may break more easily, especially when it is wet, dry or already damaged.

Relevance for hair and scalp
Mechanical hair damage can lead to hair breakage, split ends and frizzy hair. Although the hair follicles are usually not damaged, the hair can look thinner and less healthy. Gentle handling and the right tools can help reduce this type of damage.

During miniaturisation, the hair grows for a shorter time and becomes finer with each cycle. The hair follicle remains in the skin, but the hairs it produces become weaker and less visible. Over time, these hairs can become very fine. This process happens gradually, not suddenly.

Relevance for hair and scalp
Miniaturisation mainly occurs in hereditary hair loss and is an important cause of thinning hair and reduced hair density.

The scalp produces sebum through glands connected to the hair follicles. Sebum protects both the scalp and the hair. When too much sebum is produced, the oil spreads along the hair more quickly. This can make the hair look flat, shiny or unwashed. How fast this happens differs per person and depends on hair type and care habits.

Relevance for hair and scalp
Oily hair mainly affects the appearance and comfort of the hair and usually does not say anything about the health of the hair follicles.

Parabens protect products against bacteria and fungi. When used within approved limits, they are considered safe. Some people still choose to avoid parabens, for example due to sensitive skin or personal preference.

Relevance for hair and scalp
In people with sensitive skin, parabens can sometimes cause skin reactions, although this differs per person

With PCOS, the body often produces higher levels of male hormones (androgens). These hormones can cause hair on the scalp to become thinner, especially on the top of the head. At the same time, increased hair growth may occur in other areas, such as the face or body. Hair follicles on the scalp are more sensitive to these hormones, which can weaken hair growth.

Relevance for hair and scalp
PCOS-related hair loss mainly affects women and often resembles hereditary hair loss. It can influence hair density, the parting and confidence. With proper support, the process can often be slowed down.

With a receding hairline, the hair at the temples gradually becomes thinner and grows less far forward. This usually happens slowly and can become more noticeable over the years. A receding hairline is often one of the first visible signs of hereditary hair loss and can start at a young adult age.

Relevance for hair and scalp
A receding hairline develops because hair follicles in this area are more sensitive to hormonal influences. The hairs become thinner, grow shorter or eventually stop growing. While full regrowth in these areas is difficult, further progression can sometimes be slowed and the appearance can be softened with proper care or styling.

During seasonal hair loss, more hairs enter the resting phase of the hair growth cycle at the same time. A few months later, these hairs fall out. This process is linked to changes in daylight, temperature and the body’s natural rhythm. It occurs more often in regions with strong seasonal changes than in countries with a stable climate. The hair follicles remain healthy and can produce new hair afterwards.

Relevance for hair and scalp
Seasonal hair loss occurs in both men and women and usually does not lead to permanent hair thinning. It can temporarily cause more hair in the brush, shower or on the pillow, but often resolves on its own.

Sebum is produced by sebaceous glands attached to each hair follicle. It helps prevent the scalp from drying out and keeps hair flexible. Only when too much or too little sebum is produced can scalp issues arise.

Relevance for hair and scalp
Balanced sebum levels are essential for scalp health. Too much can cause oily hair and flakes, while too little can lead to dryness and irritation.

During shedding, many hairs enter the resting phase of the hair growth cycle at once. A few months later, these hairs fall out. The hair follicles remain intact and are able to produce new hair afterwards. Shedding is therefore usually temporary and reversible.

Relevance for hair and scalp
Shedding can lead to noticeably more hair in the brush, shower or on the pillow, but it usually does not cause permanent thinning or bald patches.

Silicones are often used in shampoos, conditioners and styling products. They make hair feel smooth and shiny and help reduce tangles. Some silicones rinse out easily, while others stay on the hair longer and are harder to remove.

Relevance for hair and scalp
When silicones build up on the hair, they can reduce how well water and caring ingredients penetrate the hair. This can make hair feel heavy, dry or dull and may increase breakage, especially in fine or damaged hair.

The skin barrier consists of fats and proteins that work together to keep the skin healthy. When this protective layer is disrupted, the scalp can lose moisture more easily and become more sensitive to external factors such as cold, heat or hair care products.

Relevance for hair and scalp
A well-functioning skin barrier is important for a comfortable and healthy scalp.

Commonly used sulphates include SLS and SLES. These ingredients help shampoo to foam well and clean thoroughly. However, they can also remove the scalp’s natural protective layer. This may make the scalp feel drier or more sensitive, especially with frequent use.

Relevance for hair and scalp
In people with a sensitive or dry scalp, sulphates can cause irritation or dryness.

In telogen effluvium, too many hairs enter the resting phase of the hair growth cycle at once. This leads to increased hair shedding over a short period. The hair becomes thinner across the entire scalp, without clear bald patches. The hair follicles remain healthy, which means hair can usually regrow.

Relevance for hair and scalp
Telogen effluvium is a common cause of temporary hair loss and often occurs after stress, illness or hormonal changes.

This includes shampoos, conditioners, lotions, serums and masks. Because they are applied locally, they act directly on the skin and hair.

Relevance for hair and scalp
Topical products help maintain scalp health, soften damaged hair and support hair growth.

Yeasts normally live on the skin without causing problems. When the balance of the scalp is disturbed, yeasts can multiply more quickly. This may lead to symptoms such as itching, redness and flaking. Not all itching or flaking is caused by yeast.

Relevance for hair and scalp
An imbalance of yeasts can affect scalp comfort, but usually does not cause permanent hair loss.