The loss or absence of the hairs on the scalp which were noticeable and shows its presence at any hair bearing parts of human body is called Alopecia. Generally there were three types of Alopecia.

HEREDIATARY ALOPACIA.

This type Alopecia includes male-pattern baldness which is the most common cause of Alopacia.The hairs is lost initially from the temples and crown and are substituted by fine layers of brown hairs. The most recognizable and the affected part of the scalp show normal line hair which becomes faints. This type of hair-loss patterns is primarily inherited from the generations which mainly affects men but may be formed in young women and the women are who have passed their menopause. The other forms of hereditary hair loss are rare in humans who may be due to absence of hair-roots or other abnormalities of the hair shaft mainly caused normally due of sun, wind and by the application of a shampoo and combing of the hairs.

GENARALISED ALOPACIA

In this rare form of Alopecia in which the hairs falls in large amounts leaving behind invisible covering over the whole scalp. This type of hair loss mostly happens because all the hairs together enter into the resting phase and then easily removed out in three to four months later. The complete growth of hair on the scalp has been retained, once the primary reason of the fall of hairs has detected & treated properly. This type of alopecia most frequently occur due to different causes, chiefly due to stress, a surgical operation have being performed, extended illness or at the time of child birth. Some anticancer drugs may also produce the symptoms resembling to that of Alopecia.

LOCALISED ALOPACIA.

The localized alopecia mainly occurs due to the complete damage to the skin (that is destroyed by burns and or due to radiotherapy).The other significant causes of hair loss is shock to the roots of the hair which primarily occur due to excessive pulling of the hair to produce a particular type of hair styles or rarely due to tricotillomana (disorder in which the suffering individual pulls out all the hair of the scalp). One of the significant & commonest causes of this type of hair-loss is Alopecia areta which shows its presence in the limited area of hair in which the balded skin looks and feels normal. This cause is unknown as the lost hairs returns to normal conditions within periods of few months. There is no known cause and treatments available for Alopecia araeta. Alopacia Universalis is a rare form of Alopacia areata which causes all the hairs on the scalp to be completely lost and other body parts including eyelashes and eyebrows on the individual body of humans being. The infestation of ringworm on the skin of the scalp may be another cause of Localized hair loss due to the breakage of weakened hair shaft. The other skin sickness, such as Lichen plannus, Lupus erythematosus cause the skin of the scalp to become abnormal and these skin growths mainly responsible for this type of Alopacia or mainly responsible for balded skin looks abnormal in their condition and the hair stubble can be seen in the entire affected areas.

Regardless of what the sort, alopecia areata has dependably been a reason for mental pain as a rule. On the other hand, it is vital to comprehend the distinctive sorts to choose the reparability of the cases:

• Alopecia areata monolocularis: A solitary bare spot on the scalp denote this condition. It may stay as being what is indicated or may advancement to development of numerous spots.
• Alopecia areata multilocularis: The patient presents with different bare spots on the scalp since the onset of the dissention.
• Alopecia totalis: All the hair on the scalp is lost in this kind of alopecia. It is one of the serious structures and constitutes the troublesome cases.
• Alopecia universalis: When all the hair from everywhere throughout the body is lost, the condition is called alopecia universalis.
• Alopecia barbae: The bare spots are constrained just to the facial hair area in this sort.
• Traction alopecia: In a few patients, because of consistent strain on the hair from being tied firmly,
  alopecia creates along the frontal and transient edges of the scalp bringing about footing alopecia.

There is an alternate order of alopecia focused around the vicinity of contamination on the scalp:

1. Non-scarred alopecia areata: Here there is no super added contamination of the scalp and shots of recuperation are better in such cases.
2. Scarred alopecia areata: A lichen contamination of the scalp can prompt irreversible harm to the
   follicles and the skin of the scalp making it look like scar tissue.