What are hormones and how do they work?

There are at least 50 hormones at work in your body. And just about every cell and function is under their constant influence throughout your life.

In this article, we explore why hormones are essential for your health, the system that keeps them in balance, and how you can check your hormone levels are optimal.

We cover:

• What do hormones do?
• How do they work?
• What are hormones made from?
• The endocrine system
• How to balance your hormones
• How to test your hormone levels

What do hormones do?
 

Hormones are chemical messengers that buzz around your body in your blood. They help coordinate many important processes and functions in your body by altering the activity of specific target organs and tissues.

For example, when your body’s stress (fight-or-flight) response is triggered, the hormone adrenaline is released. Adrenaline has multiple effects on your body, which prepare you to face perceived threats.

The effects of adrenaline:

• Boosts sugar levels for your body to use as a fuel
• Dilates (widens) your pupils to allow more light to enter your eyes
• Increases heart rate
• Increases respiratory rate and widens your airways (bronchodilation) to allow more oxygen into your body
• Slows down digestion by redirecting blood flow to the brain and muscles

Processes controlled by hormones include:

• Growth and development
• Homeostasis — maintaining your body’s internal balance, including regulating your body temperature, blood sugar, and blood pressure.
• Metabolism
• Reproduction
• Sexual function
• Sleep/wake cycle

Hormones also have profound effects on your mood and general wellbeing.

How do hormones work?
 

Hormones coordinate different processes in your body by carrying messages to your organs, skin, muscles, and other target tissues. They hitch a ride in your bloodstream, which means they can travel all over your body.

The cells of their target tissues have receptors that allow hormones to bind to them. A hormone can only trigger a reaction in specific cells — its so-called target cells — that have the right receptors for it.

It’s handy to think of hormones as keys and receptors as locks. If the hormone fits, the message is received, which triggers a biological reaction that affects the body.

Hormones communicate their messages in two ways:

1. Between two endocrine glands — one gland releases a hormone that stimulates another gland to change the level of hormone that it’s releasing. An example of this is the pituitary gland, which acts on the thyroid gland to regulate the level of thyroid hormones.
2. Between an endocrine gland and a target organ — for example, the pancreas releases the hormone insulin, which alerts your liver to take up excess glucose from your bloodstream to maintain healthy blood sugar levels. Insulin also allows cells around the body to take up glucose to use as a fuel source.

What are hormones made from?
 

There are three types of hormones:

1. Protein- (or peptide-) based hormones: including follicle-stimulating hormone (FSH) and the feel-good hormone, oxytocin.
2. Lipid-based hormones: mostly steroid hormones that are formed from cholesterol, including cortisol, oestradiol, and testosterone.
3. Amino acid-based hormones: simple, water-soluble molecules that include the thyroid hormones, thyroxine and triiodothyronine, and melatonin.

Where are hormones made?
 

Hormones are made in glands, organs, and tissues in your body. Many of these make up the endocrine system, which keeps your hormones in harmony like the conductor of a well-tuned orchestra.

The endocrine system controls the release of hormones and their effects on the body. It constantly monitors hormone levels using feedback loops to ensure they’re optimal.

The ten main endocrine glands:

1. Adrenals – two triangle-shaped glands above your kidneys. They make hormones that help regulate functions such as heart rate, blood pressure, and the stress response.
2. Hypothalamus – a structure in the brain that releases several hormones that control the pituitary gland. The hypothalamus is involved in many functions such as appetite, sleep/wake cycles, and body temperature.
3. Ovaries – in females, the ovaries release several hormones including oestrogen and progesterone.
4. Pancreas – the pancreas is located behind your stomach and helps control blood sugar levels.
5. Parathyroids – these four, pea-sized glands at the front of your neck control calcium levels in your blood and bones.
6. Pineal – a tiny gland in the brain that makes melatonin and is important for your sleep/wake cycle.
7. Pituitary gland – a pea-sized gland located at the base of the brain, just below the hypothalamus. It releases hormones that control growth and reproduction, and the function of other endocrine glands.
8. Testes – in males, the testes form part of the reproductive system and make the primary male sex hormone, testosterone.
9. Thymus – located in the upper torso, this gland makes hormones that are important for the immune system.
10. Thyroid gland – a butterfly-shaped gland at the front of the neck that plays a vital role in controlling metabolism — the process of converting food into energy.

Some endocrine glands also have non-endocrine functions. For instance, the ovaries and testes produce hormones, but they also have the non-endocrine function of producing sperm and eggs, respectively.

There are other organs and tissues that release hormones (and hormone-like substances) but are not considered part of the endocrine system.

Other tissues that release hormones include:

• Adipose (fat) tissue
• Gut (gastrointestinal tract)
• Kidneys
• Liver
• Placenta

What can go wrong with hormones?
 

Sometimes, hormone levels can get out of balance. This is often due to the overproduction or underproduction of one or more hormones.

Many hormone-related medical conditions involve hypo- (too little) or hyper- (too much) secretion of specific hormones.

Health conditions that affect hormones include:

• Diabetes
• Hyper- and hypothyroidism
• Polycystic ovary syndrome (PCOS)

It’s important to be aware of the symptoms of hormone imbalances, as they often go undetected. They can share symptoms with other health issues, which makes them difficult to spot. The early signs can also be subtle and may be put down to other things like a busy work week or a recent cold.

5 common hormone imbalance symptoms:  

1. Weight gain or loss — you may also find it difficult to lose weight or that you’ve lost muscle or gained fat
2. Feeling tired all the time
3. Depression and anxiety
4. Skin issues like hormonal acne
5. Reduced sex drive

How to balance your hormones
 

Sometimes, it’s possible to restore your hormone levels naturally. However, in some cases, your doctor may recommend treatment such as hormone replacement therapy (HRT) to restore your hormones to optimal levels.

Three ways to improve your hormone health naturally:

1. Follow a healthy diet — include healthy fats such as omega-3, plenty of protein and fibre, and cut out ultra-processed foods.
2. Get plenty of rest — sleep may be the best medicine when it comes to hormone health.
3. Exercise — take regular exercise, but don’t overdo it. A brisk walk or yoga class can benefit your hormone health. Exercise is also great for combating stress, which can play havoc with your hormones.

How to test your hormone levels
 

A hormone blood test can check whether your levels are within the healthy range. Your test results help you explore whether an imbalance may be contributing to your symptoms, or if you need to explore other lines of enquiry.

Not sure which test to take? Check out our Female Hormone Blood Test Buying Guide or Male Hormone Blood Test Buying Guide. Alternatively, our Test Finder can help you find the right test for you.

For more information on hormone health, visit our Hormone Health Hub.