Endocrine System:

The endocrine system is made up of glands that make hormones. Hormones are the body’s chemical messengers. They carry information and instructions from one set of cells to another. The endocrine system controls most processes in your body, from growth to sexual function. While many parts of the body make hormones, the major glands that make up the endocrine system are the:
Hypothalamus
Pituitary
Thyroid
Parathyroids
Adrenals
The Ovaries
The Testes

Relation Between Endocrine System and Hair Loss:

There are many reasons for hair loss. While many blame their genes or stress for a bald head, the actual reason may be quite different. Hormonal deficiency can also be a probable cause. Both men and women can develop hormonal imbalances that can cause hair to thin or fall out. Often, treating the imbalance helps your hair regrow. Although most people think of estrogen and androgen (hormones that are produced in the endocrine system) when they think of a hormone imbalance, issues
with your thyroid and pituitary glands (part of the endocrine system) can also lead to hair thinning.

Estrogen

Estrogen is the hormone secreted by the ovaries. Ovaries maintain the health of the female reproductive system. Estrogen hormone helps hair grow faster and stay on the head for longer periods of time. When the levels of estrogen drop, such as after a pregnancy or during and after menopause, more hair enters the “resting” phase, where it soon falls out and causes thinning and even balding patches. It also causes hair to grow more slowly and becomes much thinner. It is because before menopause, your body produces three forms of estrogen: estradiol, estriol and estrone. During menopause, your body stops producing estradiol and estriol, and only produces estrone which may leads to hair loss.

Menopause

Menopause is a natural biological process that all women experience at some point in their lives. During this time, the body goes through numerous physical changes as it adjusts to fluctuating hormone levels, hair loss during menopause is the result of a hormonal imbalance.

Androgens

An androgen is a sex hormone that contributes to the development of what are thought of as “male” sex characteristics, such as body hair. But it can also make you lose your hair faster and earlier. Both menand women make androgens, but males typically make much higher levels, which can cause androgenetic alopecia.

Androgenetic alopecia is a common form of hair loss in both men and women. The specific hormone dihydrotestosterone known as “DHT” (a hormone that your body produces as a byproduct of testosterone) is responsible for hair loss. DHT attacks your hair follicles, causing your hair to fall out and stop growing. Men typically have more testosterone than women, which may explain why baldness is more common among men.

Hypothyroidism & Hyperthyroidism

Hypothyroidism tends to make people feel tired, sluggish, depressed, and constipated. Hyperthyroidism can manifest in anxiety, problems sleeping, restlessness, and irritability. If symptoms are present, check your thyroid levels and talk to your doctor about thyroid hormone therapy. In most cases, hair grows back once thyroid abnormalities are treated.

Although women have much lower levels of testosterone than men do,
there is enough to potentially cause androgenetic hair loss. High levels of androgens, including DHT, can shrink your hair follicles as well as shorten this cycle, causing hair to grow out looking thinner and more brittle, as well as fall out faster. DHT can also make it take longer for your follicles to grow new hairs once old hairs fall out.

Thyroid hormone regulates pretty much every process in our body. Thyroid plays an important role in the development of new strands of hair at the root, helping your body maintain a consistent supply of new hairs.

Hair loss is one of the main symptoms of hypothyroidism (insufficient amounts of thyroid hormone) and paradoxically, hyperthyroidism (too much production of thyroid hormone). When the thyroid system becomes under-active, like with hypothyroidism, hair tends to be dry, brittle, dull, and diffusely thinned – even eyebrow hair can fall out. When the thyroid system becomes overactive, like with hyperthyroidism, hair will also fall out. In short, both hypothyroidism (under-active thyroid) and hyperthyroidism (overactive thyroid) can trigger hair loss. Most of the time, thyroid issues cause diffuse hair loss across your entire scalp.

Hypopituitarism is a condition in which the pituitary gland fails to secrete enough of one or several hormones. This resulting hormonal imbalance leads to changes in the growth pattern of hair and causes hair loss. In addition to balding and thinning hair, other signs and symptoms of hypopituitarism include the following:

Shedding of body hair
Decreased facial hair
Reduced weight
Fatigue and low energy

In many cases, hypopituitarism is caused by a tumor of the pituitary gland. As a pituitary tumor increases in size, it can compress and damage pituitary tissue, interfering with hormone production. In addition to tumors, certain diseases or events that cause damage to the pituitary gland may also trigger hypopituitarism such as head injuries, brain surgery and severe loss of blood during childbirth, which may cause damage to the front part of the pituitary gland.

Hair loss may accompany several endocrine disorders including hypopituitarism, hyperthyroidism hypothyroidism, growth hormone deficiency, dihydrotestosterone. Hair re-growth depends on what caused the hormonal imbalance in the first place. The causes, as seen, are many from genetic predisposition to poor diet to menopause. Sometimes, treating the hormonal imbalance can help reverse hair loss, and at other times, it may be necessary to choose hair restoration options.