Hypothyroidism & Adrenal Insufficiency: What’s the Link?

Hypothyroidism and adrenal insufficiency are both conditions that involve the endocrine organs and glands in the body. They share symptoms such as fatigue, weakness, weight fluctuation, and hair changes. Studies have found potential links between thyroid and adrenal disorders and how they can co-occur together.

Read on to learn more about hypothyroidism and adrenal insufficiency, including their symptoms, diagnosis, and management.

Hypothyroidism and Adrenal Insufficiency

The thyroid gland is a hormone-secreting (endocrine) organ located at the base of the neck. It is responsible for making the thyroid hormones thyroxine (T4) and triiodothyronine (T3).

Thyroid hormones are extremely important in regulating metabolism and temperature. When there is a deficiency, the body has trouble using energy and staying warm.

The adrenal glands are endocrine organs that sit above the kidneys. They are responsible for secreting several hormones, including:

• Cortisol (stress hormone)
• Aldosterone
• Sex hormones
• Catecholamines (epinephrine and norepinephrine)

Adrenal insufficiency is a condition where the adrenal glands do not make enough cortisol. Cortisol, like thyroid hormone, is involved in metabolism, but it also plays a role in blood pressure, blood sugar, and inflammation.

Linking Hypothyroidism and Adrenal Insufficiency

Hypothyroidism and adrenal insufficiency are different conditions, but they can share a common cause. Autoimmune disorders often affect several organs and can be responsible for causing autoimmune thyroid disease and adrenal insufficiency.

Some small studies and case reports have demonstrated a possible link between these conditions:

• A 2015 study showed that 5% of patients with autoimmune thyroid disease (including people with hyperthyroidism or hypothyroidism caused by an autoimmune disease) also had underlying primary adrenal insufficiency.
• A study in Norway found that of people with primary adrenal insufficiency, 41% also had hypothyroidism.
• An older study of critically ill patients admitted to the intensive care unit (ICU) found that 12% of them had both hypothyroidism and adrenal insufficiency. Based on these findings, the authors of the study concluded that these conditions could be closely associated.

Symptoms of Hypothyroidism and Adrenal Insufficiency

Hypothyroidism and adrenal insufficiency share some common symptoms. Low levels of thyroid hormones or of cortisol can lead to:

• Fatigue
• Decreased appetite
• Changes in weight
• Weakness
• Mood changes and difficulty concentrating
• Menstrual changes
• Gastrointestinal symptoms
• Changes in skin and hair

Other symptoms unique to low cortisol levels include:

• Changes in skin color (dark patches)
• Salt craving
• Low blood pressure
• Dizziness (particularly when standing)
  
• Low glucose

Diagnosing Hypothyroidism and Adrenal Insufficiency

Both hypothyroidism and adrenal insufficiency can be diagnosed using laboratory tests.

Hypothyroidism is diagnosed by looking at blood levels of thyroid stimulating hormone (TSH), as well as T3 and T4. High levels of TSH and low levels of T3 and T4 indicate a problem with the thyroid gland.

The first step to check for adrenal insufficiency is doing a cortisol blood test. If cortisol levels are low, the next step is an adrenocorticotropic hormone (ACTH) stimulation test.

ACTH is a hormone released by the pituitary gland that stimulates the adrenal glands to release cortisol. During this test, synthetic ACTH is given and cortisol levels in the blood are measured 30-60 minutes later. If cortisol levels do not appropriately increase after ACTH is administered, primary adrenal insufficiency is diagnosed.

If primary adrenal insufficiency is diagnosed, other hormone levels like renin and aldosterone are measured. Imaging studies, including ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI), can be done to look for abnormalities in the adrenal glands.

Treating Hypothyroidism and Adrenal Insufficiency

Both hypothyroidism and adrenal insufficiency are treated with hormone supplementation.

In hypothyroidism, artificial T4 thyroid hormone, called levothyroxine, is administered to normalize levels. Alternatively, desiccated thyroid (Armour thyroid) derived from pig thyroid glands can be prescribed. Levels of thyroid hormones are monitored over time to ensure the dosage is appropriate.

Adrenal insufficiency is also treated with hormone supplementation. The adrenal glands are responsible for making several hormones, and low levels are replaced with:

• Glucocorticoids, like hydrocortisone or prednisolone, are given to replace cortisol. Doses must be increased in times of stress (e.g., illness or surgery).
• Florinef (fludrocortisone) is given to replace mineralocorticoid hormones (another type of steroid hormone).
• Dehydroepiandrosterone (DHEA) can be given for sex hormone replacement in females with low energy levels and low libido.

Summary

Hypothyroidism and adrenal insufficiency are endocrine disorders that cause low levels of specific hormones. They have similar symptoms such as fatigue, weakness, and changes in weight, mood, and menstrual cycle

While hypothyroidism is a fairly common disorder, adrenal insufficiency is much less common. Laboratory tests can diagnose both conditions and treatment involves hormone supplementation.

A Word From Verywell

Hypothyroidism and adrenal insufficiency can both have nonspecific symptoms that can also be caused by other conditions. Diagnosing hypothyroidism or adrenal insufficiency can take some time, which can be frustrating. If low cortisol is suspected, it's important to diagnose and treat the problem before correcting or replacing low thyroid hormones. Replacing low thyroid hormones first can contribute to worsening low cortisol. Work with a healthcare provider to get a proper diagnosis and develop a treatment plan.