The causes of hair loss can be as varied as the forms it takes. Normal hair loss is when up to 100 hairs are lost every day. Hereditary factors are often responsible for hair loss. However, malnutrition, medication, psychological stress (e.g. stress and lack of sleep) or hormonal imbalances can also be the trigger or exacerbate existing hair loss symptoms.
Hereditary hair loss
The most common form of hair loss is hereditary hair loss, also known as androgenetic alopecia . It affects around 42% of women and 60-80% of men.
Depending on genetic predisposition, the first symptoms of hereditary hair loss can already appear in young adulthood. In men, the first signs of hereditary hair loss usually appear in the form of widening receding hairlines and thinning hair at the back of the head. In women, the thinning crown and receding frontal hairline is one of the most common signs of hereditary hair loss.
In androgenetic alopecia, hair loss is caused by the hormone dihydrotestosterone (DHT). This is a chemical breakdown product of the hormone testosterone. If the corresponding genetic predisposition is present, the hair follicles react very sensitively to DHT and atrophy. With each new hair growth cycle, less strong hair grows back, and the growth phase of the hair is shortened, while the resting phase is extended. This means that the hair cycle becomes shorter from time to time.
Hormonal hair loss
Pregnancy, hormonal contraceptive methods or the onset of the menopause represent a major hormonal change for the human body. For example, the greatly increased oestrogen level during pregnancy keeps the hair in the growth phase for longer and makes it appear shinier and stronger. However, 8 weeks after giving birth, oestrogen levels often drop rapidly and hair increasingly enters the resting phase (telogen phase), which makes it more susceptible to loss due to external influences such as mechanical stimuli (brushing, combing, etc.). A form of diffuse hair loss (alopecia diffusa) can now set in.
However, this phase is usually only a transition – after 6 to 12 months, the hormone balance returns to normal and hair growth usually returns with it. Hormonal contraceptive methods that are based on oestrogen can also trigger increased hair loss when discontinuing. However, this usually normalizes again after a while, as it is a hormonal imbalance caused by discontinuation.
During the menopause, oestrogen levels drop, which can lead to thinning and increased hair loss. Around a third of all menopausal women suffer from hair loss symptoms. However, it does not necessarily have to be due to the menopause if women are increasingly affected by hair loss around the age of forty: Often enough, the actual reason is the presence of a genetic sensitivity to dihydrotestosterone (DHT). This form of hereditary hair loss is also known as hereditary hormonal hair loss.
Polycystic ovary syndrome (PCO syndrome) can also trigger hormonal hair loss.
Diffuse hair loss
In this form of hair loss, which affects women more than men, the hair falls out evenly over the entire head. The causes of diffuse hair loss are varied. The positive aspect is that in most cases it is only temporary. Causes of diffuse hair loss can include hormonal imbalances, thyroid dysfunction or medication. Iron deficiency, stress and chronic illnesses are also possible causes.
Circular hair loss
In this form of hair loss, which affects women more than men, the hair falls out evenly over the entire head. The causes of diffuse hair loss are varied. The positive aspect is that in most cases it is only temporary. Causes of diffuse hair loss can include hormonal imbalances, thyroid dysfunction or medication. Iron deficiency, stress and chronic illnesses are also possible causes.
Scarring hair loss
This disease-related and rarely occurring hair loss is also known as alopecia cicatricalis or scarring alopecia. It is usually caused by an inflammation of the scalp or another disease. This not only attacks the skin, but also destroys the hair follicles and leads to scarring. As hair growth is no longer possible, a scarred and permanently bald area remains.
It is mainly viruses, fungi and bacteria that can cause inflammation of the scalp. Hair loss symptoms also occur as a result of rare autoimmune diseases or thyroid dysfunction. Physical injury, for example as a result of burns or chemical burns, can also cause scarring hair loss.