You can visit a dermatologist to determine the type of hair loss (alopecia) that you may be experiencing. Generally there are 2 types of hair loss: diffuse and limited (circumscriptive) hair loss.
I. Diffuse alopecia affects the whole head. This type of hair loss can be:
A. Congenital, or
B. Acquired. Acquired hair loss generally falls into one of 5 categories
1. acute - caused by toxins, drugs, X-rays etc;
2. chronic - caused by the same reasons as above but with lower intensity so that the hair loss is delayed;
3. progressive (male hair loss or “alopecia androgenetica”) - occurs in men and it is conditioned genetically and by age;
4. male pattern alopecia in females - caused by a hormonal disturbance in women;
5. chronic alopecia during severe diseases (infective, leukemia, autoimmune, cancers etc.).
II. Circumscriptive alopecia is limited to some areas of the head. It can be either Uncicatrixeal (reversible), or Cicatrixeal (irreversible).
A. Uncicatrixeal (reversible). This type of hair loss is categorized as either:
1. Alopecia areata - caused by an autoimmune disease;
2. Post infective - occurs after local infection on the skin;
3. Traumatic alopecia - caused by chronic pressure on some areas of skin of the head or by pulling out (extracting) hairs.
B. Cicatrixeal (irreversible) hair loss can be caused by:
1. Alopetions in congenital dermatoses;
2. Acquired – after contusions, corrosions, burning, severe local infections, X-rays etc.;
3. Specific causes.