Cortisol

What is cortisol

A hormone produced by the adrenal gland known as the stress hormone because it helps the body respond to threats however it has other functions like managing blood sugar and reducing inflammation

The 3 step stress pathway (HPA Axis)

It’s a 3 chain link

Stressor hits > hypothalamus fires

The hypothalamus senses stress and releases CRH into tiny blood vessels

CRH - the go signal for pituitary

CRH Arrives > pituitary gland releases ACTH into bloodstream and it goes to the adrenal glands

ACTH arrives > adrenal cortex makes cortisol

Negative feedback

Cortisol loops back to both:

The hypothalamus (reduces CRH)

The anterior pituitary (reduces ACTH)

Result: when cortisol is high enough, the system turns itself down as it prevents runaway hormone production and keeps levels in a healthy range

What cortisol does

Helps the body cope with stress and mobilize fuel

Raises blood glucose

Helps break down protein

Supports blood pressure

Damps inflammation and suppresses immunity

Affects attention, memory and mood during stress

When the system misfires

Too much cortisol: weight gain, thin skin, high bp, high glucose, infections

Too little cortisol: fatigue, low bp, weight loss, low sodium, meds urgent replacement if severe

How does glucose control metabolism

Increase blood sugar when your stressed

Stops insulin from lowering sugar too much

Tell the liver to make more sugar

Stops other body parts from using up too much sugar

Breaks down protein

Breaks down fat for energy

Hypercortisolism

When you have excess cortisol

Caused by too much ACTH

Hypothalamus tumour makes extra CRH

Pituitary tumour makes too much ACTH

Adrenal gland tumour makes too much cortisol

Taking too much cortisone therapy

Some cancers like ectopic cancer can make ACTH or cortisol