What Are Growth Hormones, & How Do They Work?

Human growth hormones (hGH), secreted by the pituitary gland in the body, play an important role in the development and maturation of children, maintenance of adults' normal body structure, and metabolism of both sexes.

The function of growth hormones is simple: they help children grow and develop. They aid in the maintenance of normal fluid and electrolyte balance, skeletal and muscular development, glycemic and lipolytic pathways, and perhaps even cardiac performance.

HGH is the active ingredient in a variety of prescription drugs and other products and is even produced synthetically.

You can read here about how to restore hormonal balance.

What is Growth Hormone?

Growth hormones are released by the pituitary gland. (Image via Pexels/Lukas)

Growth hormones are responsible for proper growth and development of a child. The body still requires hGH even after the growth plates in the bones (epiphyses) have fused. After puberty ends, hGH aids in the maintenance of normal body structure and metabolism, including the maintenance of normal blood sugar (glucose) levels.

Hormones are chemicals produced in the body that circulate throughout the body, sending signals to various organs, muscles, and other tissues. The body responds to these cues, which tell it what to do and when to do it. There're more than 50 hormones in the human body, and many of them interact with each other.

The pituitary gland is a tiny endocrine gland, about the size of a pea, that sits at the base of the brain, below the hypothalamus. The front lobe is called the anterior lobe, while the back lobe is called the posterior lobe. The growth hormone is produced by the anterior lobe of the pituitary.

A stalk of blood vessels and nerves links the pituitary gland with the hypothalamus. The pituitary stalk is what you see here. Functions such as blood pressure, heart rate, body temperature, and digestion are all regulated by the hypothalamus in the brain.

The hypothalamus tells the pituitary gland to secrete certain hormones via the stalk. Here, the hypothalamus secretes GHRH, which in turn stimulates the pituitary gland to secrete hGH and somatostatin, which blocks or inhibits the pituitary gland's production of hGH.

How do Growth Hormones Work?

Growth hormone continues to work long after you have grown up and developed your physical body entirely. (Image via Pexels/Samer Daboul)

Below we have listed the functions performed by growth hormones:

1) Growth

The release of HGH stimulates expansion of virtually all body parts. Still, its fame rests on the fact that it stimulates the development of bone and cartilage, particularly in adolescents. Growth hormone (hGH) sends signals to cells in cartilage and bone (called chondrocytes and osteoblasts, respectively) to multiply.

2) Metabolism

Growth hormone regulates blood sugar levels in adults. (Image via Pexels/Emma Bauso)

What we call metabolism refers to the series of chemical reactions that occur in the body to convert the food we eat into usable energy. The body's cells are constantly demanding energy to do their jobs. The metabolic process involves a wide variety of intricate steps.

The primary mechanism by which hGH affects metabolism is via an increase in the production of insulin-like growth factor-1 (IGF-1) and the cellular effects of this peptide.

IGF-1 is a hormone with similarities to insulin that controls how the body responds to hGH. Insulin, produced by the pancreas, is a crucial hormone in controlling blood sugar (glucose) levels. IGF-1 can reduce blood glucose level in a similar manner to insulin.

Normal blood glucose levels are carefully controlled by the body. Most of the sugar in the blood is in the form of glucose. Blood glucose levels are maintained by the consumption of carbohydrates. In addition to fueling the body, this sugar also nourishes the organs, muscles, and nervous system.

When blood glucose levels are too high, the pancreas produces the hormone insulin, and when they're too low, it produces the hormone glucagon. However, epinephrine (adrenaline) and cortisol are two hormones that can counteract insulin's effects.

Excess growth hormones in the body can counteract the effects of insulin, leading to elevated blood glucose level despite the fact that hGH is normally used to raise blood glucose level when they drop too low.

Normal Levels of Growth Hormones in Humans

The growth hormone is secreted in bursts by the pituitary gland. The magnitude and duration of the pulses change depending on factors such as age, gender, and time of day.

As a result, doctors can rarely rely on hGH levels obtained through random testing to either confirm or rule out a diagnosis. However, hGH tests are most informative when they're integrated into a larger stimulation or suppression study.

The following fall within the typical range of hGh concentrations:

For male adults: 18 and 44 pmol/L (or 0.4 and 10 ng/mL)
For adult females: 1-14 ng/mL (44-616 pmol/L)
For children: 10-50 ng/mL (440-2200 pmol/L)

The typical range of values may change from one laboratory to the other. When interpreting your results, make sure to compare them to the lab's normal range. Have your healthcare provider answer any questions you may have about your growth hormones.