Hypothyroidism

Hypothyroidism is when your thyroid doesn't make enough thyroid hormones.

Causes of hypothyroidism include:

In Hashimoto thyroiditis, Hashimoto Thyroiditis Your thyroid is a gland below the Adam’s apple in your neck. Your thyroid releases thyroid hormones. The hormones control how fast your body’s chemical functions work (metabolic rate). Almost... read more your body's immune system Overview of the Immune System The immune system is your body's defense system. It helps protect you from illness and infection. The immune system's job is to attack things that don’t belong in your body, including: Germs... read more mistakenly attacks your thyroid. This type of disease is called an autoimmune disease Autoimmune Diseases The immune system is your body's defense system. It helps protect you from illness and infection. The immune system usually attacks invading bacteria, viruses, and cancer cells. With an autoimmune... read more .

Lack of iodine is rare in modern countries. Most countries put a little iodine in salt so everybody gets enough. There's also iodine in seafood. People in some poor countries far from the sea are at risk of not getting enough iodine.

The pituitary gland Overview of the Pituitary Gland The pituitary gland is a pea-sized bit of tissue at the bottom of your brain. Glands are organs that make and release hormones into your blood. Hormones are chemicals that stimulate other cells... read more in your brain makes a hormone called TSH that tells your thyroid to make thyroid hormones. If you have a problem with your pituitary gland, it might not make TSH and you'll get hypothyroidism.

Not making enough thyroid hormones cause your body functions to slow down, which can affect how you look, sound, or feel.

Symptoms that affect the way you look or sound may include:

Symptoms that affect the way you feel may include:

If not treated, hypothyroidism can eventually cause:

In older people, confusion and forgetfulness may be mistaken for Alzheimer disease Alzheimer Disease Alzheimer disease is a type of dementia that usually affects people older than 65. Dementia is a brain problem that makes it hard to remember, think, understand language, and learn. Brain problems... read more or some other kind of dementia Dementia Dementia is a brain problem that makes it hard to remember, think, and learn. Most dementia begins little by little and starts after age 65. It’s normal for the brain to change with age, but... read more .

Doctors will do:

Doctors treat hypothyroidism with:

After you start the pills, your doctor will gradually adjust the dose based on your TSH level. It's important to talk to your doctor about medicines that interfere with absorbing thyroid hormone. Such medicines include iron, calcium, and some antacids.