The adrenal glands are a pair of glands located on top of both kidneys. Yellow in color and small in size, the function of these glands is to produce different hormones. Part of the adrenal gland, called the adrenal cortex, secretes three categories of hormones: glucocorticoids which include cortisol, mineralocorticoids with aldosterone in particular, and androgens such as testosterone. The other part, the adrenal medulla, secretes catecholamines, meaning adrenaline and noradrenaline. Diseases affecting the adrenal glands can reduce or completely stop the production of these hormones.