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What you need to know about hormones

Teenager popping pimple
Hormones are absolutely essential to the workings of every cell in your body.

You've probably heard of oestrogen and testosterone – the primary female and male sex hormones. But did you know that there are many other types of hormones that help your body to function?

Hormones are chemical messengers that send signals to your brain, heart, bones, muscles, and reproductive organs. They’re vital to the workings of every cell in your body.

From the time you’re born, your hormones dictate your appetite, sleep patterns, how you respond to stress, your libido, whether you’re happy or anxious, and everything in between.

Here are five hormones you might not have heard of before, what they do and why they matter.

1. The ‘sleep’ hormone

Melatonin is the hormone released by your brain to make you feel either sleepy at night time or awake during the day.

When it’s dark, melatonin is slowly released, telling your body it’s time to go to sleep. Being around too much bright light before bed can affect the level of melatonin that is released. It’s also why it can be hard for some night-time shift workers to sleep during the day.

Melatonin levels stay elevated for most of the night while you’re in the dark. Then, they drop in the early morning as the sun rises, causing you to wake up.

If you’re looking for a better night’s sleep, sticking to a consistent sleep, wake and meal schedule can help generate melatonin.

Woman sleeping

2. The ‘stress’ hormone

A near miss, an approaching deadline or an imminent danger – Cortisol is one of your main stress hormones and is released by your adrenal glands, during stressful situations.

When released, it causes your heart rate and blood pressure to increase and triggers your body’s natural ‘flight or fight’ response. Once the perceived threat has passed, cortisol levels drop and your other systems return to normal.

However, when cortisol levels are too high for too long, this hormone can cause weight gain and high blood pressure, disrupt sleep, negatively impact mood, reduce your energy levels and contribute to diabetes. When they are too low, they can make you feel extremely tired and can lead to low blood pressure that could result in a fall.

While a little bit of stress can be a good thing, helping you to focus and perform well under pressure, ongoing stress is not healthy for your body or mind.

Some strategies for decreasing stress are: knowing what triggers your stress, practising relaxation techniques, setting achievable goals, making time for activities you enjoy, and using tools like to-do lists to help you set priorities. Here’s a great blog on ways to reduce your stress right now.

Mother and daughter meditating

3. The 'love' hormone

It goes without saying that love is more complicated than just a chemical reaction, but the hormone oxytocin is commonly credited with helping you bond with your loved ones.

It's released during physical contact, so a cuddle with your pet, a neighbour or a potential partner can all help you to bond on some level.

This hormone also plays a crucial role in birth and motherhood. It’s the chemical messenger that tells the uterus to contract, beginning labor. It then helps move the process along by increasing the production of related hormones. After delivery, it helps the uterus return to its previous size.

When a baby latches on their mother’s breast, it triggers a release of oxytocin. This signals the body to let down milk for the baby.

A young man hugging an older man

4. The 'hunger' hormone

Got a grumbly tummy? You can thank the ‘hunger’ hormone produced in your gut called Ghrelin.

Ghrelin is a hormone that sends a signal to your brain to feel hungry. The higher your levels, the hungrier you get. The lower your levels, the fuller you feel. Ghrelin also tells your gut to start making the digestive acids and juices that will allow it to break down the foods you eat. 

Another hunger hormone, Leptin, is produced by your body’s fat cells and tells you to feel satisfied after you have eaten. When you have enough fat stored, it sends messages to your brain that you don't need to eat anymore and can start burning kilojoules at a normal rate.

5. The 'thirst' hormone

Another really important hormone, called vasopressin, controls the water levels in your body.

If your body feels like it has enough water, this hormone will trigger the need to pee. However, if you are dehydrated or very hot, it will tell your body to release less water and pee less – that's when your urine goes really dark.

Hands pouring water

Last updated: 15 March 2019