Cortisol is likely the culprit.
Cortisol isn’t bad, and we need healthy levels on cortisol to be balanced.
Cortisol should be naturally high in the morning (around 7am) and gradually decrease throughout the day. The lowering of cortisol allows melatonin in, which will promote a restful sleep.
You will not produce melatonin naturally if cortisol is high.
Cortisol is produced by your adrenal glands, after signaling from your brain.
Chronic stress can result a surge in adrenal hormones (like adrenaline and cortisol), causing them to remain high or rise and fluctuate drastically through the night – which inevitably makes it more difficult to get a restful sleep.
Regulating your cortisol rhythm can be with simple dietary and lifestyle changes.