A class of hormones, two of which are known to be important in a medical emergency. These are epinephrine and norepinephrine . Dopamine and Dopa are also catecholamines. All the catecholamines stimulate high blood pressure and can trigger symptoms usually associated with threatening situations leading to a panic attack.

Epinephrine
Adrenaline

An hormone released by the adrenal gland , which is the drug of choice for the treatment of anaphylaxis . Indeed those who are allergic to insect stings and cetain foods should always carry a self-injecting syringe of epinephrine.

Epinephrine increases the speed and force of heart beats and, therefore the work that can be done by the heart. It dilates the airways to improve breathing and narrows blood vessels in the skin and intestine so that an increased flow of blood reaches the muscles and allows them to cope with the demands of exercise. Usually treatment with this hormone stops an anaphylactic reaction. Epinephrine has been produced synthetically as a drug since 1900.

Norepinephrine
Noradrenaline

Also an hormone released by the adrenal gland . Norepinephrine is released, along with Epinephrine, from the adrenals and from nerves when heart failure takes place. These hormones are the first line of defence during any sudden stress. The release of these hormones cause the heart to pump faster, making up for the pumping problem caused by heart failure.