Central hypothyroidism is when your thyroid hormone levels are low because your hypothalamus or pituitary gland isn’t functioning properly.

Hypothyroidism — also called an underactive thyroid — is a hormonal issue in which your body produces fewer thyroid hormones than necessary. Central hypothyroidism occurs when the hypothalamus or pituitary gland isn’t stimulating the thyroid gland enough.

In other words, the problem isn’t the thyroid gland itself, but the pituitary gland or hypothalamus.

Common symptoms of central hypothyroidism include fatigue, hair loss, and depression. You may also experience pain or stiffness in your muscles and joints.

Although hypothyroidism is relatively common, central hypothyroidism is rare. Globally, central hypothyroidism affects 1 in 20,000 to 1 in 80,000 people. Only 1 in 1,000 people with hypothyroidism have central hypothyroidism.

Central hypothyroidism is a condition in which your thyroid levels are low because your pituitary gland, hypothalamus, or both aren’t functioning correctly.

Your thyroid gland produces hormones that are essential for your bodily functions. The primary thyroid hormones are thyroxine (T4) and triiodothyronine (T3). Thyroid hormones play an important role in your cardiovascular health and digestive system.

But in order to keep a healthy level of thyroid hormones, the following needs to happen:

  • The hypothalamus releases thyrotropin-releasing hormone (TRH).
  • TRH, in turn, stimulates the pituitary gland to release thyroid-stimulating hormone (TSH).
  • TSH then stimulates the thyroid gland to produce thyroid hormones.

When the thyroid is healthy, but the hypothalamus isn’t producing TRH, the pituitary gland isn’t releasing TSH, or both, the thyroid won’t produce thyroid hormones. This is central hypothyroidism.

Central hypothyroidism doesn’t include hypothyroidism that occurs because your thyroid gland itself isn’t functioning correctly. This is called primary hypothyroidism.

Clinicians also categorize the condition as primary, secondary, or tertiary hypothyroidism.

Both secondary hypothyroidism and tertiary hypothyroidism are a form of central hypothyroidism. Central hypothyroidism isn’t as common as primary hypothyroidism.

The symptoms of central hypothyroidism differ from person to person. Some may experience more severe symptoms than others.

Thyroid hormones play an important role in many bodily functions. They affect the metabolism, reproductive system, muscle function, and more.

Symptoms of central hypothyroidism include:

Many of the symptoms of central hypothyroidism could also be symptoms of other health conditions.

Healthcare professionals diagnose hypothyroidism using blood tests.

They might test for:

  • thyroid hormones (especially free T4 levels)
  • TSH
  • thyroid antibodies

In most cases of hypothyroidism, TSH levels are high, but with central hypothyroidism, TSH levels are usually low. But it’s possible to have standard or slightly high TSH levels while having central hypothyroidism. This TSH might be biologically inactive.

A healthcare professional may need to run further tests to figure out whether you have central hypothyroidism or another form of hypothyroidism. They might order an MRI scan of the brain to look at the hypothalamus and pituitary gland.

Central hypothyroidism occurs when the pituitary gland, the hypothalamus, or both aren’t functioning as they should.

This can be caused by a few different factors, including:

  • brain tumors on the pituitary gland or hypothalamus
  • damage to the pituitary gland or hypothalamus from surgery, traumatic brain injury, or radiation treatment
  • inflammatory or autoimmune diseases that affect the pituitary gland
  • Sheehan syndrome, a rare condition in which the pituitary gland is damaged by significant blood loss, usually during or after childbirth
  • some medications, including prednisone and opioids
  • traumatic brain injury

In order to determine the cause of your condition, a healthcare professional might run brain scans or blood tests.

Risk factors for central hypothyroidism

Certain factors can put you at an increased risk of developing central hypothyroidism.

These factors include:

  • family history of pituitary tumors
  • genetic conditions that affect the pituitary gland or hypothalamus
  • history of brain surgery or brain tumors
  • history of using certain medications, including opioids and prednisone
  • radiation therapy to the brain
  • severe head injury

People of any age and gender can develop central hypothyroidism.

Hypothyroidism is usually treated with thyroid hormone replacement therapy, usually in the form of levothyroxine (Levoxyl, Synthroid).

Levothyroxine is a synthetic version of T4. Your body can produce T3 from the synthetic T4.

After a few weeks of treatment, you may experience some relief from your symptoms. Your symptoms may become more manageable or even disappear altogether.

You may need to have regular blood tests to ensure that you’re getting the right dosage. A healthcare professional might adjust your dosage based on your blood tests.

If you have central hypothyroidism because of a tumor, you might have to have surgery to remove the tumor.

Certain lifestyle changes and self-care strategies might also help with the symptoms of hypothyroidism. For example:

Although there’s no specific diet for hypothyroidism, eating an adequate amount of iodine-rich foods is important for thyroid function.

Does central hypothyroidism shorten life expectancy?

When appropriately treated, central hypothyroidism itself doesn’t usually shorten life expectancy.

But the underlying cause of central hypothyroidism (e.g., pituitary tumor) might affect your life span and quality of life.

If left untreated, severe central hypothyroidism can lead to complications like myxedema coma. This is a life threatening condition that requires emergency care. Untreated hypothyroidism may also lead to heart failure.

But with the right treatment, people with hypothyroidism can have a positive quality of life and an average life expectancy.

Central hypothyroidism is a rare form of hypothyroidism. It occurs when the pituitary gland or hypothalamus (or both) doesn’t produce the hormones your thyroid gland needs to function properly. This may be due to a tumor, a brain injury, or a genetic issue.

When you receive the right treatment, the symptoms of central hypothyroidism may become more manageable or disappear altogether. Speaking with a healthcare professional is the first step in treating your condition.