Hormone therapy for breast cancer 2: The role of hormones

Hormones are made naturally in your body. They control the growth and activity of normal cells. All your hormones are produced by different organs and glands, which together are known as the endocrine system.

The ovaries produce the hormones oestrogen and progesterone. Throughout your life, your body depends on oestrogen to keep you healthy and strong. Without oestrogen, your overall health and wellbeing will be impacted.

Oestrogen is one of the main sex hormones and it influences nearly every organ in your body including: your reproductive system, sex drive, skin, mood, brain function, heart, and bone health. It also controls how you burn fat and build muscle.

Oestrogen plays a role during puberty, regulation of periods and sexual development. It also plays an important role in the growth and maintenance of healthy bones throughout your lifetime.

As you age, oestrogen helps to protect your bones. Oestrogen helps keep your blood vessels healthy and can prevent inflammation of the heart, so it is vital for a healthy heart.

It controls cholesterol levels and increases the production of good cholesterol. It is also important for controlling blood sugar.

Oestrogen boosts the production of the brain chemical serotonin. Serotonin balances your mood. For example, during menopause: when oestrogen levels decrease or drop, people often report mood swings, feeling very emotional, or low mood, which can lead to depression.

People also notice that their ability to concentrate, find words or names or multi-task, changes after menopause, again showing the role of oestrogen for brain function.