Many things can cause excessive hair loss. For example, you may suddenly lose a large amount of hair about 3 or 4 months after an illness or major surgery. This hair loss is related to the stress of the disease and is temporary.
Iron deficiency causes anemia. Less oxygen is carried to the scalp, starving the follicles, and eventually causing gradual, uniform hair loss. Vitamin C deficiency and consumption of caffeine and alcohol can also interfere with iron absorption. Drinking fruit juice along with iron-rich foods helps hair grow back.
The growing phase of the hair cycle is stopped prematurely by eating less food. Hair loses its shine and falls out. People who suddenly lose weight, or limit their caloric intake to maintain a low weight, may also have dry, dull-looking hair. The cure is to eat protein right in breakfast especially and without skipping meals, not foods lacking in nutrients. Too much vitamin A and lack of protein are the main reasons.
Family history (heredity)
This is one of the major causes of hair loss due to hereditary conditions like male and female pattern baldness. It is said to have predictable patterns and symptoms such as decreased hair lines and bald spots in men and thinning of hair in women that occurs gradually as one ages
Hormonal changes and medical conditions
There is always some hormonal imbalance or problem in our body which leads to other changes and many such conditions can cause temporary or permanent hair loss. It can be caused by conditions of pregnancy, changes in the menstrual cycle or due to menopause, childbirth or thyroid problems. Medical conditions such as alopecia areata that cause hair loss, scalp infections such as ringworm or excess lice and a hair-pulling disorder called trichotillomania
Medications and supplements
Hair loss can be a side effect of certain medications, such as those used for cancer, arthritis, depression, heart problems, gout, and high blood pressure. Also anti depressants, blood thinners, extreme fitness supplements also made cause.
Many people experience a general thinning of hair several months after a physical or emotional shock or setback. This type of hair loss is temporary but can be of high degree due to excess stress, tension, family issues.
Hair fall can also be caused due to chemical trauma, extensive usage of chemical treatments, causes irritation in scalp and can sufficiently damage that section of hair.