The endocrine system is a network of glands that
produce and release hormones that help control
many important body functions, especially the
body's ability to change calories into energy that
powers cells and organs. The endocrine system
influences how your heart beats, how your bones
and tissues grow, even your ability to make a
baby. It plays a vital role in whether or not you
develop diabetes, thyroid disease, growth
disorders, sexual dysfunction and a host of other
hormone-related disorders.
Glands of the endocrine system
Each gland of the endocrine system releases
specific hormones into your bloodstream. These
hormones travel through your blood to other cells
and help control or coordinate many body
processes.
Endocrine glands include:

Adrenal glands. T
wo glands that sit on top of
the kidneys that release the hormone cortisol.
Hypothalamus . A part of the lower middle
brain that tells the pituitary gland when to
release hormones.
Ovaries .
The female reproductive organs that
release eggs and produce sex hormones.
Islet cells in the pancreas . Cells in the
pancreas control the release of the hormones
insulin and glucagon.
Parathyroid.
Four tiny glands in the neck that
play a role in bone development.
Pineal gland . A gland found near the centre of
the brain that may be linked to sleep patterns.
Pituitary gland .
A gland found at the base of
brain behind the sinuses. It is often called the
"master gland" because it influences many
other glands, especially the thyroid. Problems
with the pituitary gland can affect bone growth,
a woman's menstrual cycles and the release of
breast milk.
Testes .
The male reproductive glands that
produce sperm and sex hormones.
Thymus. A gland in the upper chest that helps
develop the body's immune system early in
life.
Thyroid.
A butterfly-shaped gland in the front
of the neck that controls metabolism.
Even the slightest hiccup with the function of one
or more of these glands can throw off the delicate
balance of hormones in your body and lead to an
endocrine disorder, or endocrine disease.

Causes of endocrine disorders.

Endocrine disorders are typically grouped into two
categories:
Endocrine disease that results when a gland
produces too much or too little of an endocrine
hormone, called a hormone imbalance.
Endocrine disease due to the development of
lesions (such as nodules or tumours) in the
endocrine system, which may or may not affect
hormone levels.
The endocrine's feedback system helps control
the balance of hormones in the bloodstream. If
your body has too much or too little of a certain
hormone, the feedback system signals the proper
gland or glands to correct the problem. A
hormone imbalance may occur if this feedback
system has trouble keeping the right level of
hormones in the bloodstream, or if your body
doesn't clear them out of the bloodstream
properly.
Increased or decreased levels of endocrine
hormone may be caused by:
A problem with the endocrine feedback system
Disease
Failure of a gland to stimulate another gland to
release hormones (for example, a problem with
the hypothalamus can disrupt hormone
production in the pituitary gland)
A genetic disorder such as multiple endocrine
neoplasia (MEN) or congenital hypothyroidism
Infection
Injury to an endocrine gland
Tumour of an endocrine gland
Most endocrine tumours and nodules (lumps) are
non-cancerous. They usually do not spread to
other parts of the body. However, a tumour or
nodule on the gland may interfere with the
gland's hormone production.

Types of endocrine disorders
There are many different types of endocrine
disorders. Diabetes is the most common
endocrine disorder diagnosed in the UK.
Other endocrine disorders include:
Adrenal insufficiency. The adrenal gland releases
too little of the hormone cortisol and sometimes,
aldosterone. Symptoms include fatigue, stomach
upset, dehydration and skin changes. Addison’s
disease is a type of adrenal insufficiency.
Cushing's disease. Overproduction of a pituitary
gland hormone leads to an overactive adrenal
gland. A similar condition called Cushing's
syndrome may occur in people, particularly
children, who take high doses of corticosteroid
medications.
Acromegaly and other growth hormone problems.
If the pituitary gland produces too much growth
hormone, a child's bones and body parts may
grow abnormally fast. If growth hormone levels
are too low, a child can stop growing in height.
Hyperthyroidism . The thyroid gland produces too
much thyroid hormone, leading to weight loss,
fast heart rate, sweating and nervousness. The
most common cause of an overactive thyroid is
an autoimmune disorder called Grave's disease.
Hypothyroidism. The thyroid gland does not
produce enough thyroid hormone, leading to
fatigue, constipation, dry skin and depression. The
underactive gland can cause slowed development
in children. Some types of hypothyroidism are
present at birth.
Hypopituitarism. The pituitary gland releases little
or no hormones. It may be caused by a number
of different diseases. Women with this condition
may stop getting their periods.
Multiple endocrine neoplasia I and II (MEN I and
MEN II). These rare, genetic conditions are
passed down through families. They cause
tumours of the parathyroid, adrenal and thyroid
glands, leading to overproduction of hormones.
Polycystic ovary syndrome (PCOS).
Overproduction of androgens interfere with the
development of eggs and their release from the
female ovaries. PCOS is a leading cause of
infertility.
Precocious puberty. Abnormally early puberty that
occurs when glands tell the body to release sex
hormones too soon in life.
Testing for endocrine disorders
If you have an endocrine disorder, your doctor
may refer you to a specialist called an
endocrinologist. An endocrinologist is specially
trained in problems with the endocrine system.

Testing for endocrine disorders .
The symptoms of an endocrine disorder vary
widely and depend on the specific gland involved.
However, most people with endocrine disease
complain of fatigue and weakness.
Blood and urine tests to check your hormone
levels can help your doctors determine if you have
an endocrine disorder. Imaging tests may be done
to help locate or pinpoint a nodule or tumour.
Treatment of endocrine disorders can be
complicated, as a change in one hormone level
can throw off another. Your doctor or specialist
may arrange routine blood tests to check for
problems or to determine if your medication or
treatment plan needs to be adjusted.