Hair thickness

# What is hair thickness? Hair thickness is an important characteristic that has not only aesthetic but also functional effects on human health and well-being. Hair thickness describes the diameter of a single hair and can vary greatly both between and within individuals. In general, hair thickness can be influenced by a variety of factors. Genetic predisposition, environmental conditions and general health are important determinants. For example, genetic differences between individuals can lead to considerable variations in hair thickness. Hormonal changes, ageing and dietary habits also play a role in determining hair thickness. Compared to other hair characteristics, such as hair color or hair texture, hair thickness is particularly important for the stability and strength of the hair. Thicker hair tends to be more resistant to breakage and damage. This is particularly important when assessing hair loss or damage, as changes in hair thickness can often be an early sign of underlying health problems or environmental stresses. Changes in hair thickness can also affect cosmetic perception. Thicker hair is often perceived as healthy and strong, while thinner hair can be seen as less healthy. This perception can be influenced by cosmetic products and treatments that aim to improve hair thickness or increase hair volume. In scientific research, hair thickness is often studied to understand relationships between genetic factors and phenotypic traits. Studies have shown that certain genetic variants are associated with hair thickness and can therefore influence individual variation in hair thickness. These findings contribute to the development of new approaches for the treatment of hair disorders and the improvement of hair care products. # Physiological factors Hair thickness can be influenced by a variety of physiological factors, both internal and external. One of the most important physiological factors is the health of the hair follicles, which regulate hair growth. A healthy scalp promotes strong hair, as the follicles are supplied with sufficient nutrients and have a stable environment. Chronic health problems such as thyroid disease or malnutrition, on the other hand, can lead to a reduction in hair thickness. Inadequate blood circulation or hormonal imbalances can also impair the supply of nutrients to the hair follicles and lead to thinning hair. > ## Good to know > > The average hair thickness of dark-haired people is often greater than that of blondes. These differences can be up to 40% and contribute to the diversity of hair textures. # Care and environmental factors Care and environmental factors play an important role in influencing hair thickness. Frequent styling, chemical treatments such as coloring or perming and the use of heat styling appliances can negatively influence hair thickness by damaging the hair structure and leading to a loss of volume. Environmental factors such as UV radiation, air pollution and extreme weather conditions can also affect hair thickness. UV rays can thin the hair by damaging the outer protective layer of the hair, the cuticle. Exposure to harmful environmental substances can also stress the hair and reduce its thickness. Regular care, protection and avoiding harsh treatments can help maintain hair thickness and keep hair healthy. # What does genetics have to do with it? The SNP rs4752566 in the FGFR2 gene is an important marker for hair thickness, especially in Asian populations. FGFR2, the fibroblast growth factor receptor 2, plays a key role in regulating hair growth and follicle development. This gene is part of a network of signaling pathways that influence the size and density of hair follicles. The variations in the FGFR2 gene identified by the SNP rs4752566 can modulate the activity of this signaling pathway and thus influence hair density. Studies have shown that certain alleles of rs4752566 are associated with a significant increase in hair thickness. This suggests that individuals with these alleles tend to have thicker hair than individuals with other alleles. This association emphasizes the importance of FGFR2 as a regulatory element in hair follicle development. The SNP rs3827760 in the EDAR gene is another important genetic marker for hair thickness. EDAR, or ectodysplasin A receptor gene, is a protein-coding gene that influences hair follicle morphogenesis and is crucial for the development of hair structure. Variations in the EDAR gene can change the size and shape of hair follicles, which has a direct effect on hair thickness. The EDAR gene is responsible for the formation and function of hair follicles, and certain alleles can alter receptor function, resulting in thicker hair. These observations are consistent with the fact that EDAR is an important contributor to variation in hair structure between different populations, particularly in relation to hair thickness.