Understanding Addison's Disease
In Addison's disease, the adrenal cortex is damaged, resulting in insufficient production of hormones. The condition affects approximately 1 in 100,000 people and can occur at any age, though it's most common between ages 30-50. Women are slightly more likely to develop the condition than men.
Types of Adrenal Insufficiency
- Primary (Addison's disease): Direct damage to adrenal glands
- Secondary: Pituitary gland doesn't produce enough ACTH
- Tertiary: Hypothalamus doesn't produce enough CRH
Symptoms
Symptoms usually develop slowly over months and may be vague initially, often leading to delayed diagnosis:
Common Symptoms
- Extreme fatigue: Worsens over time
- Weight loss and decreased appetite: Unintentional
- Hyperpigmentation: Darkening of skin, especially in creases, scars, lips, and gums
- Low blood pressure: May cause dizziness or fainting
- Salt craving: Due to sodium loss
- Low blood sugar: Hypoglycemia
- Nausea, vomiting, or diarrhea: Gastrointestinal symptoms
- Abdominal pain: Often vague
- Muscle or joint pain: Generalized weakness
- Irritability and depression: Mood changes
- Loss of body hair: Particularly in women
- Sexual dysfunction: In women
Adrenal Crisis (Addisonian Crisis)
A life-threatening emergency that can occur if Addison's disease is untreated or during times of physical stress:
- Sudden penetrating pain in lower back, abdomen, or legs
- Severe vomiting and diarrhea
- Dehydration
- Low blood pressure
- Shock
- Loss of consciousness
- High potassium (hyperkalemia) and low sodium (hyponatremia)
Causes
Autoimmune Destruction (70-90% of cases)
The most common cause in developed countries. The immune system mistakenly attacks the adrenal cortex, gradually destroying it. This may occur alone or as part of autoimmune polyendocrine syndromes.
Infections
- Tuberculosis: Most common cause worldwide
- HIV/AIDS: Can affect adrenal function
- Fungal infections: Histoplasmosis, coccidioidomycosis
- Cytomegalovirus: In immunocompromised patients
Other Causes
- Cancer metastases: Spread to adrenal glands
- Hemorrhage: Bleeding into adrenal glands
- Genetic disorders: Adrenoleukodystrophy, congenital adrenal hyperplasia
- Medications: Drugs that inhibit cortisol synthesis
- Surgical removal: Bilateral adrenalectomy
Diagnosis
Laboratory Tests
- ACTH Stimulation Test: Gold standard for diagnosis
- Morning Cortisol: Low levels suggest insufficiency
- ACTH Levels: Elevated in primary insufficiency
- Electrolytes: Low sodium, high potassium
- Blood Sugar: May be low
- Adrenal Antibodies: Present in autoimmune cases
Imaging Studies
- CT Scan: May show small or enlarged adrenals
- MRI: For pituitary evaluation in secondary insufficiency
- Chest X-ray: To check for tuberculosis
Additional Testing
- Thyroid function tests
- Tests for other autoimmune conditions
- Genetic testing in young males
- TB testing if suspected
Treatment
Hormone Replacement Therapy
Lifelong hormone replacement is necessary to replace missing hormones:
- Hydrocortisone: Most common glucocorticoid replacement
- Typical dose: 15-25 mg daily in divided doses
- Mimics natural cortisol rhythm
- Alternative: Prednisone or dexamethasone
- Fludrocortisone: Mineralocorticoid replacement
- Typical dose: 0.05-0.2 mg daily
- Helps maintain sodium and potassium balance
- Dose adjusted based on blood pressure and electrolytes
Stress Dosing
During illness or stress, cortisol requirements increase:
- Minor illness/stress: Double usual dose
- Moderate illness: Triple usual dose
- Severe illness/surgery: IV hydrocortisone
- Prevention: Carry emergency injection kit
Managing Adrenal Crisis
- Immediate IV hydrocortisone (100 mg)
- IV fluid resuscitation with saline
- Correction of hypoglycemia
- Treatment of precipitating cause
- Continuous monitoring
Living with Addison's Disease
Daily Management
- Take medications exactly as prescribed
- Never skip doses
- Carry extra medication
- Wear medical alert identification
- Keep emergency injection kit available
- Regular follow-up appointments
Lifestyle Adjustments
- Diet: Maintain adequate salt intake, especially in hot weather
- Exercise: Regular activity with appropriate hydration
- Stress Management: Learn to recognize and manage stress
- Travel: Carry extra medication and medical documentation
- Vaccinations: Stay up-to-date to prevent infections
Emergency Preparedness
- Educate family and friends about your condition
- Create an emergency action plan
- Keep written instructions for emergency treatment
- Maintain communication with healthcare team
- Know signs of impending crisis
Potential Complications
- Adrenal Crisis: Life-threatening emergency
- Electrolyte Imbalances: Can affect heart rhythm
- Hypoglycemia: Low blood sugar episodes
- Depression: Due to chronic illness
- Osteoporosis: From long-term steroid use
- Associated Autoimmune Conditions: Thyroid disease, type 1 diabetes
Prognosis
With proper treatment and management, people with Addison's disease can lead normal, active lives with a normal life expectancy. Key factors for good outcomes include:
- Early diagnosis and treatment
- Adherence to medication regimen
- Proper stress dose management
- Regular medical follow-up
- Patient education and empowerment
- Emergency preparedness
The most significant risk is adrenal crisis, which can be prevented through proper management and prompt treatment during times of stress or illness. With modern treatment, death from adrenal crisis is rare but remains a risk if the condition is not properly managed.