How is cortisol related to an adrenal imbalance?

Too Much/Too Little. While the adrenal gland makes several hormones, too little or too much cortisol is usually the problem for adrenals that are under- or overactive. Adrenal insufficiency, or failure, causes weight loss, muscle weakness, low blood pressure, and can be fatal. In cushing's syndrome (too much cortisol) weight gain, the face may be round, and there is increased risk for diabetes and high bp.
Adrenal hormones. Cortisol is one of the major hormones produced by the adrenal gland. Dysfunction of the adrenal gland or hormones that control adrenal gland function may affect cortisol production.