Cortisol: What is it? Actions of This Compound, Properties, Function and Deficiency

It is an organic compound that belongs to the steroid family and is the primary hormone secreted by the adrenal glands.

Cortisol is also called hydrocortisone.

It is a potent anti-inflammatory agent and is used for the palliative treatment of several conditions, including itching caused by dermatitis or insect bites, inflammation associated with arthritis or ulcerative colitis, and diseases of the adrenal glands.

Almost all cells contain receptors for cortisol, so cortisol can have many different actions depending on the type of cells it acts on.

A similar version of this hormone, known as corticosterone, is produced by rodents, birds, and reptiles.

Cortisol actions

Cortisol is the main glucocorticoid in humans. It has two main actions: it stimulates gluconeogenesis (the breakdown of proteins and fats to provide metabolites that can be converted to glucose in the liver) and activates anti-stress and anti-inflammatory pathways.

It also has weak mineralocorticoid activity. Cortisol plays a vital role in the body’s response to stress.


It helps maintain blood glucose concentrations by increasing gluconeogenesis and blocking glucose absorption in tissues other than the central nervous system.

It also contributes to maintaining blood pressure by increasing the constrictive effects of catecholamines in blood vessels.

Cortisol properties

Cortisol, along with more powerful and longer-acting synthetic derivatives such as prednisone, methylprednisolone, and dexamethasone, has potent anti-inflammatory and anti-allergic actions. At the cellular level, glucocorticoids inhibit the production and activity of inflammatory cytokines.

In high doses, glucocorticoids can alter the function of the immune system, reducing cell-mediated immune reactions and reducing the production and action of antibodies.

Reducing immune system function with glucocorticoids helps prevent transplant rejection and treat allergic or autoimmune diseases, such as rheumatoid arthritis and disseminated lupus erythematosus.

However, these beneficial effects are outweighed by the severe side effects of high doses of glucocorticoids, especially when given over a long period.

Manifestations of chronic exposure of the body to excessive glucocorticoids can be observed in patients with Cushing’s syndrome.

Additionally, glucocorticoids are generally not used in patients with infectious diseases because immunosuppressive and anti-inflammatory actions can allow the infection to spread.

How is cortisol found in the body?

Cortisol exists in serum in two forms. Most cortisol is in the bound form, bound to cortisol-binding globulin (transcortin), while the remaining amount of cortisol is in the free or unbound state.

As free cortisol leaves the serum to enter cells, the pool of free cortisol in the serum is replenished with cortisol released from the transcortin or new cortisol secreted from the adrenal cortex.

In the cytoplasm of a target cell, cortisol binds to a specific receptor. The cortisol receptor complex then enters the nucleus of the cell.

In the nucleus, the complex activates or inhibits the transcription of specific genes, thereby altering the production of messenger ribonucleic acid (mRNA) molecules that direct the synthesis of many proteins, including enzymes and structural proteins.

Unlike cortisol, aldosterone and adrenal androgens do not bind as quickly to serum proteins. Although small amounts of cortisol and other steroid hormones are excreted in the urine, most hormones are inactivated in the liver or other tissues.

Have you ever felt stressed?

Most of us have at a certain point. Our body responds to stress in many different ways, but one thing that all stress has in common is that it increases the level of a potent hormone which is cortisol.

Cortisol is involved in regulating metabolism in cells and helps us handle stress within the body.

This hormone is synthesized from cholesterol and belongs to the group of hormones called glucocorticoids. Cortisol is produced in the adrenal cortex of the adrenal gland near the kidney.


Cortisol, like all steroid-based hormones, is a powerful chemical. Steroid-based hormones have a common mechanism of action, as they enter cells and modify gene activity in DNA.

The amount of cortisol in your body is determined by the amount of stress you are experiencing. Also, your caffeine consumption, eating patterns, physical activity you get, and sleeping patterns affect the amount of cortisol released into your system.

As a general rule of thumb, your highest cortisol level occurs right after you wake up in the morning, and the lowest level is at night while you are falling asleep.

The primary function of cortisol is to save us when we are under stress. As mentioned above, cortisol does this by causing the cell to make glucose from proteins and fatty acids; this process is known as gluconeogenesis.

What cortisol is doing is saving glucose for the brain and forcing the body to use fatty acids from stored fat for energy.

Cortisol also forces the breakdown of stored proteins into amino acids so that the body can use them to make enzymes or repair cells.

Cortisol raises blood pressure, increasing blood flow and distributing glucose and other nutrients as quickly as possible to cells.

Cortisol is used in treatments such as hydrocortisone cream to control inflammatory conditions, such as rashes and allergies. It can also be injected to treat more serious autoimmune diseases, such as rheumatoid arthritis.


Hyposecretion, or cortisol deficiency, can result from damage to the adrenal glands. This damage can cause Addison’s disease.

People affected by Addison’s disease have low blood glucose and sodium levels, increased potassium, and tend to lose weight.

This can also cause low blood pressure and dehydration. Cortisol deficiency is usually treated with corticosteroid replacement therapy to return cortisol to normal levels.