Noradrenaline

Noradrenaline (norepinephrine) governs attention, focus and alertness. It is formed from dopamine by dopamine β-hydroxylase (which depends on vitamin C). In the brain, noradrenaline is involved in attention and drive; the value in blood or urine, however, comes mainly from the body's sympathetic nerve endings and mainly shows the activity of the stress nervous system.

What noradrenaline does in the body

Noradrenaline is made from dopamine; the enzyme dopamine β-hydroxylase needs vitamin C and copper for this. It acts in two places: in the brain, nerve cells of the locus coeruleus release noradrenaline and thereby control wakefulness, attention and the response to new stimuli. In the rest of the body it is the messenger of the sympathetic nerves; a smaller part comes from the adrenal medulla. Via α1 receptors it narrows the blood vessels and thereby maintains blood pressure, and via β1 receptors it increases heart rate and the force of contraction; its effect on blood sugar is weaker than that of adrenaline. After release, most of it is taken back up into the nerve endings and the rest is broken down via COMT and MAO. The value in blood and urine comes mainly from the sympathetic nerve endings and shows their activity.

Low noradrenaline – what happens in the body?

When little noradrenaline is released, the blood vessels do not contract sufficiently when standing up: blood pools in the legs, blood pressure drops, and dizziness, blackouts in front of the eyes and tiredness when standing can occur. Temperature regulation and adaptation to exertion also become weaker. Low values occur with damage to the autonomic nerves, for example in long-standing diabetes or some neurological diseases, very rarely with an inborn lack of dopamine β-hydroxylase, and with medications that dampen the sympathetic nervous system.

High noradrenaline – what happens in the body?

When noradrenaline rises, the vessels narrow more: blood pressure rises, the hands and feet become cooler and the heart beats faster. In the brain, more noradrenaline increases wakefulness and responsiveness to stimuli, which can make it harder to fall asleep and stay asleep. Higher values arise with physical exertion, when standing, with cold, pain, emotional tension, lack of sleep and low blood sugar, when stopping certain medications and with heart failure, in which the body supports the circulation via the sympathetic system. Very high or episodically raised values are clarified by a doctor.

The interpretation is given in your report.