Cortisol Physiological Functions

Cortisol Associated Diseases and Disorders

physiological functions of cortisol, one of the most vital hormones for maintaining balance in the body:

🧬 What Is Cortisol?

• Cortisol is the primary glucocorticoid hormone produced by the adrenal cortex (zona fasciculata).
• It is released in response to stress, under control of the HPA axis:
  • Hypothalamus → CRH
  • Pituitary → ACTH
  • Adrenal glands → Cortisol

🔑 Physiological Functions of Cortisol

1. 🔄 Metabolism Regulation

Cortisol is crucial for maintaining energy balance, especially during fasting or stress:

• Increases gluconeogenesis in the liver → raises blood glucose
• Breaks down proteins (catabolism) for amino acids
• Mobilizes fats for energy (lipolysis)
• Reduces glucose uptake in peripheral tissues (insulin antagonism)

✅ Goal: Maintain blood glucose and energy during stress or fasting

2. 🛡️ Anti-Inflammatory & Immunosuppressive

Cortisol regulates immune function by:

• Inhibiting cytokine production (e.g., IL-1, IL-6, TNF-α)
• Suppressing T-cell activation and inflammation
• Reducing histamine release and stabilizing mast cells

✅ Used therapeutically as steroids (e.g., prednisone) in autoimmune or inflammatory conditions

3. 😰 Stress Response (“Fight or Flight”)

As part of the HPA axis, cortisol:

• Helps the body adapt to physical and psychological stress
• Supports cardiovascular tone, blood pressure, and alertness
• Works with adrenaline to handle acute stress

✅ Known as the “stress hormone”

4. 💧 Fluid Balance & Blood Pressure

Cortisol helps maintain vascular tone and enhances the effect of catecholamines (like norepinephrine).

• Mild mineralocorticoid activity: promotes sodium retention and potassium excretion (less than aldosterone)

✅ Supports normal blood pressure and fluid balance

5. 🧠 Mood & Cognitive Function

Cortisol receptors are found in the hippocampus, amygdala, and prefrontal cortex:

• Regulates mood, motivation, and memory
• Both low and high levels are linked to:
  • Depression
  • Anxiety
  • Memory problems
  • Sleep disturbances

6. 🦴 Bone and Skin Effects

• Inhibits bone formation (reduces osteoblast activity)
• Promotes bone resorption → prolonged excess may cause osteoporosis
• Thins the skin with prolonged high levels

7. ⏰ Circadian Rhythm

• Follows a daily cycle:
  • Highest in the early morning (around 6–8 AM)
  • Lowest at night (midnight)
• Regulates wakefulness and energy cycles

⚖️ Cortisol Balance is Critical

Too Little (Adrenal insufficiency)	Too Much (Cushing’s syndrome)
Fatigue, low BP, hypoglycemia	Weight gain, high BP, hyperglycemia
Weakness, salt craving	Muscle wasting, skin thinning
Depression, darkening of skin (ACTH↑)	Mood swings, osteoporosis

Cortisol Associated Diseases and Disorders