The key difference between primary and secondary Addison’s disease is that primary Addison’s disease happens due to the immune system attacking adrenal glands and damaging the adrenal cortex, while secondary Addison’s disease happens due to a lack of a hormone called adrenocorticotropic (ACTH).
Addison’s disease is a medical condition that results in adrenal hypofunction or adrenal insufficiency. Adrenal insufficiency occurs when the adrenal glands do not make enough hormones, such as cortisol. Addison’s disease is mainly divided into two types: primary and secondary Addison’s disease.
CONTENTS
1. Overview and Key Difference
2. What is Primary Addison’s Disease
3. What is Secondary Addison’s Disease
4. Similarities – Primary and Secondary Addison’s Disease
5. Primary vs Secondary Addison’s Disease in Tabular Form
6. Summary – Primary vs Secondary Addison’s Disease
What is Primary Addison’s Disease?
Primary Addison’s disease is a very rare type of Addison’s disease. This condition develops when the immune system attacks the adrenal glands and the outer layer of the adrenal glands (adrenal cortex) is damaged. This reduces the levels of hormones, like cortisol, which are produced by the adrenal glands. Thus, it leads to primary Addison’s disease. The other possible causes of primary Addison’s disease may include tuberculosis, infections (AIDS or fungal infections), hemorrhage, cancer, amyloidosis, surgical removal of both adrenal glands, adrenoleukodystrophy (ALD), and certain treatments needed for Cushing’s syndrome.
The symptoms of primary Addison’s disease include lack of energy, loss of appetite, dizziness, low blood pressure, hyperpigmentation, craving for salty foods, feeling sick, muscle weakness, abdominal pain, lethargy, frequent urination, increased thirst, difficulty concentrating, headaches, a higher temperature than normal, irregular periods, loss of pubic hair and hair under armpits, and puberty later than usual.
Moreover, primary Addison’s disease is diagnosed through physical examination, blood tests, synacthen stimulation test, thyroid function test, CT scan, and MRI. Some of the treatment options for primary Addison’s disease are medicines such as hydrocortisone, dexamethasone, dehydroepiandrosterone (DHEA), and lifestyle support.
What is Secondary Addison’s Disease?
Secondary Addison’s disease is a type of Addison’s disease that is due to a lack of a hormone called adrenocorticotropic (ACTH). ACTH hormone normally stimulates cortisol production by the adrenal glands. This disease may occur due to panhypopituitarism, isolated failure of ACTH production, patients receiving high doses of inhaled, intra-articular or topical corticosteroids, patients who have stopped taking corticosteroids, and failure of the hypothalamus to stimulate pituitary ACTH production. The symptoms of this condition may include severe fatigue, loss of appetite, nausea, vomiting, diarrhea, muscle weakness, irritability, depression, hypoglycemia, and coma.
Moreover, secondary Addison’s disease can be diagnosed through physical examination, blood tests such as serum cortisol test, serum ACTH test, ACTH stimulation testing, and central nervous system imaging (CT scan and MRI). Furthermore, treatment options for secondary Addison’s disease may include hydrocortisone or prednisone/prednisolone (glucocorticoid replacement) and managing panhypopituitarism, other pituitary deficiencies, and lifestyle support.
What are the Similarities Between Primary and Secondary Addison’s Disease?
- Primary and secondary Addison’s disease are two different types of Addison’s disease.
- Both conditions result in adrenal hypofunction and low serum cortisol.
- They may show similar symptoms, such as fatigue, weakness, weight loss, nausea, vomiting, and diarrhea.
- Both conditions can be diagnosed through physical examination, blood tests, and imaging tests.
- They are treated through glucocorticoid replacement and lifestyle support.
What is the Difference Between Primary and Secondary Addison’s Disease?
Primary Addison’s disease occurs due to our immune system attacking adrenal glands and damaging the adrenal cortex, while secondary Addison’s disease occurs due to a lack of a hormone called adrenocorticotropic (ACTH). Thus, this is the key difference between primary and secondary Addison’s disease.
Furthermore, primary Addison’s disease can be caused by autoimmune conditions, tuberculosis, infections (AIDS or fungal infections), hemorrhage, cancer, amyloidosis, surgical removal of both adrenal glands, adrenoleukodystrophy (ALD), and certain treatments needed for Cushing’s syndrome. On the other hand, secondary Addison’s disease is caused by panhypopituitarism, isolated failure of ACTH production, patients receiving high doses of inhaled, intra-articular or topical corticosteroids, patients who have stopped taking corticosteroids and failure of the hypothalamus to stimulate pituitary ACTH production.
The below infographic presents the differences between primary and secondary Addison’s disease in tabular form for side-by-side comparison.
Summary – Primary vs Secondary Addison’s Disease
Primary and secondary Addison’s disease are the two main types of Addison’s disease. Both conditions can cause adrenal hypofunction, which leads to low serum cortisol levels. Primary Addison’s disease occurs when the immune system attacks adrenal glands and damages the adrenal cortex. Secondary Addison’s disease occurs due to a lack of a hormone called adrenocorticotropic (ACTH). So, this is the summary of the difference between primary and secondary Addison’s disease.
Reference:
1. “Treatment – Addison’s disease.” NHS Choices, NHS.
2. Grossman, Ashley B. “Secondary Adrenal Insufficiency – Endocrine and Metabolic Disorders.” MSD Manual Professional Edition, MSD Manuals.
Image Courtesy:
1. “Addison’sLegs” By James Heilman, MD – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “HPA axis combined” By Oddcomb – Own work (CC BY-SA 4.0) via Commons Wikimedia