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.

Symptoms of hyperparathyroidism include gastrointestinal issues, like nausea, vomiting, or constipation; as well as fatigue; confusion; and muscle weakness.

Excess calcium can also be deposited in the kidneys, causing kidney stones. Treatment options include surgery or medications to control serum calcium levels.

With hypoparathyroidism, on the other hand, there’s too little PTH, which leads to low serum calcium levels, or hypocalcemia.

Symptoms of acute hypocalcemia are referred to as “tetany.” Tetany ranges from mild, presenting with numbness around the mouth, loss of sensation in the hands and feet, muscle cramps; to severe, presenting with seizures.

Chronic hypocalcemia may cause fatigue, muscle weakness, as well as eye and teeth problems. Treatment options include calcium, vitamin D, as well as a synthetic form of PTH.

Finally, let’s look at adrenal hormone excess and deficiency. Adrenal hormone excess usually refers to cortisol excess as seen in Cushing syndrome.

Signs of Cushing syndrome include obesity, especially around the abdomen, associated with thin upper and lower limbs; a round face sometimes called a “full-moon face;” a buffalo hump, which is a pocket of fat on the neck and upper back; as well as easy bruising and muscle weakness.

Because cortisol also increases blood pressure and blood sugar levels, people with Cushing syndrome also develop hypertension and hyperglycemia, leading to diabetes.

Treatment is aimed at lowering cortisol levels, either through adrenal or pituitary surgery or by using medications that block cortisol synthesis.

Adrenal hormone deficiency, on the other hand, is often caused by Addison’s disease, which is when the adrenal cortex is destroyed, and so, it can’t secrete any adrenal hormones anymore.

This results in cortisol and other adrenal hormone deficiencies. Symptoms include low blood pressure; muscle weakness; weight loss; anorexia; skin hyperpigmentation, which is when skin color darkens; and sometimes, salt craving.

Treatment includes synthetic hormone replacement therapy that acts just like adrenal hormones would. All right, as a quick recap… Growth hormone excess causes gigantism in children and acromegaly in adults.

With gigantism, children are taller but well-proportioned, whereas with acromegaly, adults typically have larger feet, hands, and facial features, which gives a disproportionate appearance.

Growth hormone deficiency causes short stature in children and no symptoms in adults. Hyperthyroidism causes heat intolerance; weight loss; anxiety; sweating; and fast, irregular heart beat, while hypothyroidism causes cold intolerance; weight gain; fatigue; slow heart rate; and pale, cold skin.

Hypoparathyroidism causes low serum calcium, whereas hyperparathyroidism causes high serum calcium, so symptoms of parathyroid hormone imbalances are caused by hypocalcemia and hypercalcemia, respectively.

Adrenal hormone excess causes Cushing syndrome, and signs include trunk obesity with thin limbs, a “full-moon face,” a buffalo hump, easy bruising, muscle weakness, hypertension, and hyperglycemia.

Finally, adrenal hormone deficiency can be caused by Addison disease, and symptoms include fatigue, weakness, weight loss, anorexia, skin hyperpigmentation, and salt craving.