Learn about Cortisol: Function and Health Effects

"Doctor, I have been under a lot of stress for a while due to the pressure of work. Recently, my stomach and face have become bigger, and my arms and legs are getting thinner. I feel very tired and I can't sleep at night." Ruwan, 35, came to our clinic with great anxiety. He thought he was suffering from a condition called "Adrenal Fatigue."

But the real medical reason is different. The main hormone that manages stress in our body is the hormone cortisol. Let's simply understand the real medical background behind Ruwan's symptoms and how the hormone cortisol affects the functioning of our body.

Cortisol is a steroid hormone in the group of glucocorticoids. It is produced and secreted by the adrenal glands, which are located above our kidneys. Cortisol acts like the body’s natural alarm system. It also helps manage many important processes that occur regularly in the body. Its production is controlled by a complex network of communication between the brain (specifically the hypothalamus and pituitary gland) and the adrenal glands.

The various functions of cortisol: beyond the stress response

Although stress management is a major function, cortisol actually affects almost every organ system in the body. Here are some of its main functions:

#### 1. Controlling the body's stress response

When a short-term or long-term stressor occurs, the body quickly releases hormones like adrenaline to respond (i.e., "fight or flight"). Cortisol joins in, helping to keep the body alert and provide the necessary energy. It does this by releasing glucose - a sugar - from the liver. This is what provides the energy needed to deal with the stress.

#### 2. Metabolism and blood sugar control

Cortisol is a hormone essential for metabolism - the way the body uses energy - and it also helps regulate blood sugar levels by controlling how insulin and glucagon work, controlling how fat, muscle and liver cells use glucose.

#### 3. Controlling Inflammation

In the short term, cortisol acts as a natural anti-inflammatory, helping to reduce inflammation in the body. However, if cortisol levels are high for a long time, it can have the opposite effect. That is, it can increase inflammation and weaken the immune system over time.

#### 4. Managing blood pressure

Cortisol has also been shown in medical science to help regulate blood pressure. When cortisol levels rise and fall, there is a direct correlation between the rise and fall of blood pressure.

#### 5. Affecting the Circadian Rhythm

Cortisol levels naturally rise and fall throughout the day. They peak just before you wake up in the morning and drop to their lowest levels at bedtime. This circadian rhythm is important for both good sleep and waking up refreshed.

What if cortisol levels are too high? (Hypercortisolism)

Having high cortisol levels all the time (a condition called Cushing's Syndrome) is not good for your health. It is rarely caused by everyday stress alone. The most common causes are:

• Medications: Long-term use of high doses of corticosteroid medications (e.g., prednisolone).
• Tumors: Tumors in the pituitary gland or adrenal glands can cause excessive production of cortisol or the hormones that stimulate its production (especially ACTH - Adrenocorticotropic Hormone).

#### Common symptoms of high cortisol levels:

People who have had high cortisol levels for a long time may experience these symptoms:

• Significant weight gain, especially in the face ("moon face") and abdomen. There may also be thinning of the limbs.
• Fat deposits behind the shoulders ("Buffalo hump").
• Wide, purple stretch marks, especially on the abdomen.
• Muscle weakness.
• Increased blood sugar levels (this can lead to type 2 diabetes).
• High blood pressure (Hypertension).
• Bruising easily.
• Fragile bones (Osteoporosis).
• In women, hair follicle growth like in men (hirsutism) or irregular menstrual periods.

What if cortisol levels drop too low? (Adrenal Insufficiency)

Adrenal insufficiency is an abnormally low level of cortisol. This means that the adrenal glands do not produce enough cortisol. The main reasons for this are:

• Primary adrenal insufficiency (Addison's disease): This is usually caused by an autoimmune condition. This means that the body's own immune system attacks the adrenal glands. Infection or other damage can also cause it.
• Consensus/Secondary adrenal insufficiency: Problems with the pituitary gland (such as tumors, decreased function) result in decreased production of the hormone ACTH, which signals the body to make cortisol. It can also occur after suddenly stopping long-term corticosteroid medication.

#### Symptoms of low cortisol levels:

• Persistent severe fatigue and a feeling of weakness.
• Weight loss for no reason.
• The food is tasteless.
• Low blood pressure (hypotension) (may cause fainting upon standing).
• Nausea, vomiting, or stomach upset.
• Muscle or joint pain.
• Browning of the skin (Hyperpigmentation) - especially in Addison's disease.

🚨 Symptoms of Adrenal Crisis that require immediate medical attention

A fatal adrenal crisis can occur when the cortisol hormone drops too quickly below the body's normal levels. You should seek emergency medical attention immediately if you experience the following symptoms:

• Sudden severe pain: Sudden, severe pain in the lower back, abdomen, or legs.
• Severe vomiting and diarrhea: Persistent vomiting and diarrhea that paralyzes the body.
• Shock: A drop in blood pressure that causes loss of consciousness or fainting.
• Drowsiness and confusion: Drowsiness or confusion that occurs with high fever.

🛠️ Action Steps to Keep Cortisol Hormone Balanced

• Step One: If you suspect you have a cortisol hormone problem, see an endocrinologist immediately and get a hormone test (saliva, blood, or 24-hour urine test).
• Step Two: Avoid taking steroid medications such as Prednisolone or Dexamethasone, which are available from pharmacies without a doctor's prescription.
• Step Three: If you are diagnosed with a condition such as Cushing's syndrome or adrenal insufficiency, take the hormone replacement medication prescribed by your doctor as directed.
• Step Four: Make it a habit to go to bed and wake up at the same time every day to maintain your body's circadian rhythm.
• Step Five: Practice meditation, deep breathing, and active exercise to reduce stress.

📊 Differences in hormonal imbalance (Cushing's vs Addison's)

📖 Sources and Scientific References

• NHS (UK) Guidance on Addison's Disease: NHS Addison's Disease Overview (Accessed 2026)
• NCBI Bookshelf Endocrine Review: Physiology of Cortisol and Adrenal Function (StatPearls - NBK538239)