Losing hair is a physiological process, present in the life of every person. Each day, we lose hair and each day new hair starts to grow back on our skin and scalp. We speak of hair loss in case of excessive loss in hair.

In Latin, hair loss is called "alopecia".

Excessive hair loss may be observed in various conditions related to specific diseases of the scalp skin, as well as a result of physiological changes (such as the so-called postpartum alopecia). In such cases, only the extent of the phenomenon is decisive in whether it is a pathological condition or not.

Excessive hair loss may result from genetic predispositions or be induced by an environmental factor. The first group includes androgenetic alopecia, which is undoubtedly the most frequent type of hair loss. The second group includes such examples of alopecia as drug-induced hair loss or hair loss resulting from an exposure to chemical factors.

There are many pathological conditions where alopecia is a primary condition, which means that the pathological process first attacks the hair follicle. Sometimes, secondary hair loss may be observed, where hair follicles are in a way "drawn" into the pathological condition, and which may primary affect other skin structures.

The decrease of the amount of hair may not result from hair loss, but from an increased tendency to break.

Apart from the above-mentioned androgenetic alopecia, commonly-seen conditions are telogen effluvium, alopecia areata, cicatrical alopecia and hair loss related to hair damage by beauty treatments (chemical, thermal damage, hair being pulled off). Some of the less frequent forms of hair loss are not only difficult to diagnose, but also to notice.

In case of some forms of excessive hair loss, it is typical that the patient sees many healthcare specialists before a correct diagnosis is made.

A correctly-made diagnosis is a key moment in the process of effective treatment. It is especially important in relation to the types of alopecia where it is possible to restore the initial hair condition.