Types of hair loss

Age-related Alopecia

is common in people over the age of 50 when the rate of hair loss increases above 50-150 hairs per day. Hair grows in cycles ranging from two to six years and when you get older, this cycle slows down and will eventually stop (dependent on the individual's lifespan). This means that towards the telogen phase of the hair growth cycle, the hair may not begin at the start of the cycle again.

Causes:
 Age
 Diet and lifestyle

Alopecia Areata

is a condition that often begins in early childhood, teenage years or young adulthood. The most common type of Alopecia Areata involves hair loss in one or more round spots (about the size of a large coin) on the scalp. The area of hair loss may tingle or be slightly painful.

Hair tends to fall out over a short period of time, with the loss commonly occurring more on one side of the scalp than the other. Because it causes bald spots on the scalp, especially in the first stages, it is sometimes called spot baldness. Alopecia Areata can take two other forms.

In approximately 1%-2% of cases, the condition can be identified as Alopecia Totalis, or Alopecia Universalis.

Alopecia Totalis is the name given to complete hair loss on the scalp. The British Association of Dermatologists estimates that 14-25% of people with Alopecia have Alopecia Totalis.

Alopecia Universalis causes complete absence of head and body hair, including eyelashes and eyebrows, along with underarm and genital hair. This is the most severe form of Alopecia Areata and is also one of the rarest.

Causes:
 Auto-immune disease
 Illness & Stress
 Thyroid dysfunction

Androgenic Alopecia

is believed to be the most common and wide spread hair loss type known today. Medical News Today reports that more than 70% of all men and about 50% of all women will be afflicted with androgenic alopecia at some point in their lives.
In men it is commonly known as Male Pattern Baldness.

It often starts around the late 20s to 30s and affects over 50% of men over the age of 50. Hair is lost in a well-defined pattern, beginning above both temples and thinning at the crown. Over time, the hairline recedes to form a characteristic "M" shape and often progresses to partial or complete baldness.

In women, it is often known as Female Pattern Baldness and differs to the male version. The hair becomes thinner all over the head, rather than receding, and it rarely leads to total baldness.

Causes:
 Hereditary
 Diet & lifestyle
 Polycystic Ovary Syndrome (PCOS)

Telogen Effluvium

is when an abnormal amount of hair falls out (over 50-150 hairs per day) usually creating a thinning appearance of hair while the scalp will look relatively healthy.

This type of hair loss is most commonly noticed when excess hair is found on your pillow or in the shower. Telogen Effluvium is a form of temporary hair loss and identification is easiest by looking at causes (below).

Causes:
 Illness & stress
 Post birth
 Menopause
 Diet & lifestyle
 Medication

Traction Alopecia

is commonly identified when hair loss is in the frontal and temporal regions. It is also easily distinguished when the hair is either weak or where the hair around the bald patches is comparably healthy and strong. Identification is easiest by looking at causes (below) which relate to overzealous styling of hair.

Causes:
 Overstyling

Anagen Effluvium

is hair loss related to chemotherapy or radiation therapy that is used to treat cancer. Initially it causes patchy hair loss, which often then becomes total hair loss.

Causes:
 Medication

Alopecia Mucinosa

is a relatively rare form of hair loss that leaves scaly patches on the skin, in which the follicles are unusually prominent and irritated/spotty.

Causes:
The causes of alopecia mucinosa are relatively unknown.

Other

hair loss can be a consequence or side-effect of other primary medical concerns, including:

 Trichotillomania (a psychological impulse control disorder causing the individual to pull out hair)
 Tinea Capitis (A fungal ringworm infection contracted from animals which can cause hair to appear stubbly)