Hormones

The rapid "fight or flight" hormone released in moments of danger or excitement.

Controls salt and water balance and blood pressure.

Lowers blood calcium — the counterpart to parathyroid hormone.

The main stress hormone, following a daily rhythm that peaks in the morning.

The "motivation and reward" chemical that drives goal-seeking and movement.

Signals the bone marrow to make red blood cells.

Drives egg and sperm production.

The "hunger" hormone that rises before meals to make you eat.

Insulin's opposite — it raises blood sugar when it drops too low.

Drives growth in childhood and tissue repair and metabolism in adults.

The key that lets cells take in glucose from the blood for energy.

The "satiety" hormone that signals the brain that you have enough energy stored.

Triggers ovulation and testosterone production.

The "darkness" hormone that signals night-time and promotes sleep.

A stress hormone and neurotransmitter that maintains alertness and blood pressure.

The main group of female sex hormones, central to the menstrual cycle.

The "bonding" hormone involved in birth, breastfeeding and connection.

The main controller of calcium levels in the blood.

Prepares the womb for pregnancy and balances oestrogen.

Drives breast-milk production and influences fertility.

A neurotransmitter and hormone involved in mood, appetite and digestion.

The main male sex hormone, also important in smaller amounts for women.

The pituitary's signal telling the thyroid how much hormone to make.

The thyroid hormones that set the body's overall metabolic rate.

The antidiuretic hormone that controls how much water the kidneys keep.