What causes alopecia (hair loss)?

Excessive hair loss has different meanings for men and women. They will need to be handled differently. Here is a non-exhaustive overview of the possible causes of alopecia.

• In humans: genetic and hormonal factors must be considered. Some men are more affected by alopecia than others and the hereditary factor is very important. In fact, you will be much more likely to go bald if your father and grandfather were bald before you. Furthermore, the most common alopecia in men is what we call androgenic alopecia, due to male hormones. This type of alopecia is banal and very common. It affects on average one in two men around the age of 50!
• In women: alopecia can be multifactorial and the origin is much more difficult to determine than in men. Hormonal factors should be considered: female hormones play a rather protective role (compared to male hormones) even if hormonal disruption can be the cause of transient alopecia (menstruation, puberty, menopause). Additionally, some women suffer from hyperandrogenism. This more or less pathological excess of male hormones will also be the cause of diffuse hair loss in women. Alopecia can also be due to a seasonal factor. More significant hair loss is observed in autumn and spring. During the first half of pregnancy, increased hair loss is possible as well as one month after delivery. Finally, lack of iron can be the cause: menstruation, an unbalanced diet, multiple pregnancies are all causes of iron deficiency in a healthy woman.
• In children: alopecia in a child should always be the subject of a medical consultation. Indeed, excessive hair loss in a child is, most often, a symptom of an underlying local or systemic pathology.

The causes of alopecia in general

Certain more general causes can induce alopecia in both men and women:

• Lack of vitamins, minerals and trace elements. A lack of iron or anemia can cause excessive hair loss. A poor diet or following a too strict diet can be the source of deficiencies in iron, B vitamins and zinc, necessary to maintain healthy hair and nails.
• Alcohol and tobacco also negatively influence the growth of hair and nails and weaken the integuments (more general name given to hair and nails).
• Stress, depression or chronic fatigue are all factors that can alter hair quality. However, even intense stress will only play a minor role in hair loss. In the event of significant alopecia, stress cannot be the only cause and another diagnosis must be established.
• Chronic eczema and dermatoses localized on the scalp can hinder proper hair growth and weaken hair bulbs. The itching they cause induces scratching lesions, which are not conducive to optimal growth.
• Certain systemic diseases: cancers, autoimmune diseases, etc. It is important to rule out any systemic cause before symptomatic treatment of even minor alopecia.
• Traction alopecia: this alopecia is caused by too much and too frequent traction on the hair. Mats, elastics, barrettes, regular straightening, reduce the vascularization of the hair bulb and weaken the hair.

Other causes can also cause alopecia.

• Thyroid problems: hypo or hyperthyroidism can be the cause of excessive hair loss.
• Drug treatments (oral contraceptives when the dose or active ingredient is not appropriate, certain antiepileptics or antihypertensives, chemotherapy, etc.). Be careful, it is essential to never stop medication treatment without medical advice. Talk to your doctor to find the combination that will be most appropriate while reducing side effects.
• Ringworm or alopecia areata