Endocrine system: Hormone insufficiency and excess

The endocrine system works best when a moderate amount of each hormone is secreted in order to maintain homeostasis, or balance in the body.

But if too little of a particular hormone is secreted, that causes a hormone insufficiency in the body. Conversely, if too much of a particular hormone is secreted, that causes a hormone excess in the body. Both hormone insufficiency and excess can cause disease.

A few relatively common causes of hormone deficiency and excess are related to growth hormone, or GH; thyroid hormones; parathyroid hormone, or PTH; and glucocorticoid hormones, especially cortisol.

So let’s look at them one by one, starting with GH. GH normally acts on various tissues in the body, making them, well, grow!

It’s also very important during childhood and adolescence, which are accelerated growth periods, and it plays a less important role in adults. So, growth hormone deficiency and excess present differently depending on the client’s age.

In children, growth hormone deficiency leads to short stature, but the person is overall well-proportioned; whereas growth hormone excess causes gigantism, which is when the child is taller than average, but still well-proportioned.

In adults, on the other hand, growth hormone deficiency doesn’t cause a clinical condition, because adults are, well, pretty much done growing.

Growth hormone excess in adults, though, causes acromegaly. Individuals with acromegaly are not well-proportioned because the bones in the face, hands, and feet grow too much, causing a characteristic appearance.

Next up, thyroid hormone excess and deficiency are quite common, and these are usually because of a disorder of the thyroid gland.

Iodine is used to synthesize thyroid hormone, and it can be found in fish, dairy, and also in iodized salt. It can also cause thyroid hormone imbalances if too much or too little is consumed.

Thyroid hormone excess is called hyperthyroidism, and it’s often caused by Graves disease, which is an autoimmune disease where your own immune system attacks the thyroid gland.

Because thyroid hormones speed up cellular metabolism, with hyperthyroidism, all the cells go in overdrive, and this results in symptoms like increased hunger associated with surprising weight loss; increased sweating and intolerance to heat; insomnia; and a fast, sometimes irregular, heart rate.

Treatment options vary depending on cause and includes anti-thyroid medications, surgically removing part or all of the gland, or using radioactive iodine to destroy some or all of the thyroid.

Hypothyroidism, on the other hand, is when there’s too little thyroid hormones, and this can also be because of thyroid or pituitary dysfunction as well as iodine deficiency.

In newborns, congenital hypothyroidism can occur. Congenital means “present from birth,” and it causes symptoms like impaired physical and mental development.

In adults, hypothyroidism manifests in the opposite way of hyperthyroidism. So, some signs and symptoms of hypothyroidism include weight gain; intolerance to cold; fatigue; slow heart rate; thinning, frail hair; and cold, pale skin.

Luckily, both congenital and adult hypothyroidism can be managed with a medication that is a synthetic form of Thyroid Stimulating hormone or TSH.

Now, remember that behind the thyroid are the parathyroid glands, which secrete parathyroid hormone, or PTH. PTH normally increases blood calcium levels.

When the parathyroid glands secrete too much PTH, this is called hyperparathyroidism, and it results in high serum calcium, or hypercalcemia.