Disease: hypothyroidism
Question: for hypothyroidism, what causes hypothyroidism??
Answer: The most common causes of hypothyroidism are:
Hashimoto�s thyroiditis
radioactive iodine treatment
thyroid surgery
radiation therapy
medications
iodine deficiency
Less common causes include:
pituitary disorders
congenital disease
pregnancy
de Quervain thyroiditis
Hashimoto�s thyroiditis
Your immune system is designed to protect your body�s cells against invading bacteria and viruses. When unknown bacteria or viruses enter your body, your immune system responds by sending fighter cells to destroy the foreign cells.
Sometimes, your body confuses normal, healthy cells for invading cells. This is called an autoimmune response. If the autoimmune response isn�t regulated or treated, your immune system can attack healthy tissues. This can cause serious medical issues, including conditions such as hypothyroidism.
Hashimoto�s thyroiditis is an autoimmune condition and the most common cause
of an underactive thyroid in the United States. This disease attacks your thyroid gland, causing damage that reduces thyroid function.
It most often affects middle-aged women, but it can occur in men and children. This condition also runs in families. If a family member has received a diagnosis of this disease, then your risk of having it is higher.
Radioactive iodine treatment for hyperthyroidism
If your thyroid gland produces too much thyroid hormone, you have a condition known as hyperthyroidism. Treatment for this condition aims to reduce and regulate thyroid hormone production.
Standard treatment for hyperthyroidism uses radioactive iodine to destroy thyroid cells. This may cause the levels of your thyroid hormone to remain low permanently.
Surgical removal of your thyroid
If your entire thyroid gland is removed as a result of thyroid problems, you�ll develop hypothyroidism. Using thyroid medication long term is the primary treatment.
If only a portion of the gland is removed, your thyroid may still be able to produce enough hormones on its own. Blood tests will help determine how much thyroid medication you may need.
Radiation therapy
If you�ve received a diagnosis of cancer of the head or neck, lymphoma, or leukemia, you may have undergone radiation therapy. Radiation used for the treatment of these conditions may slow or halt the production of thyroid hormone, leading to hypothyroidism.
Medications
Several medications may lower thyroid hormone production, resulting in hypothyroidism. These include ones used to treat mental health conditions, cancer, or heart disease, such as:
lithium, which treats mania in bipolar disorder
interleukin-2 (IL-2), an immunotherapy drug
anti-CTLA-4 medications, which treat melanoma
amiodarone (Pacerone), an antiarrhythmic drug
stavudine, a medication for HIV
Iodine deficiency
Iodine deficiency occurs infrequently in the United States, but it is the most common cause of hypothyroidism in other parts of the world. Iodine, which is needed to produce thyroid hormone, is found in foods including:
iodized salt
dairy
seafood
eggs
If you have iodine deficiency, you may develop swelling at the base of your neck. This is called a goiter. It�s caused by an enlarged thyroid gland.
Pituitary disorders
Hypothyroidism may also result from problems involving the pituitary gland. This small gland in the brain produces hormones that affect many bodily functions, including the thyroid gland.
Problems with the pituitary gland may cause thyroid issues. Pituitary disorders may result from:
pituitary tumors
medications like dopamine and opioids
radiation therapy around the brain
Sheehan syndrome, which damages the pituitary gland
This type of hypothyroidism is called secondary hypothyroidism because the thyroid gland functions normally. It�s less common than primary hypothyroidism, which is caused by a problem with the thyroid gland.
Congenital disease
Congenital hypothyroidism is hypothyroidism that�s present in children from birth. It affects between 1 in 2,000 and 1 in 4,000 newborns and is twice as common in females.
The condition occurs when the thyroid gland develops abnormally or is not present at all. Genetics or iodine deficiency may cause this. While some babies may show no symptoms, others will be less active or have trouble feeding.
U.S. hospitals test newborns for the condition. It�s important to treat congenital hypothyroidism to prevent it from delaying growth or mental development.
Pregnancy
Around 5
to 10 percent
of pregnant people will develop postpartum thyroiditis several months after their pregnancy. While only some will need treatment, others will develop permanent hypothyroidism.
The following can increase the risk of postpartum thyroiditis:
history of postpartum thyroiditis
presence of antibodies to thyroid peroxidase in the blood
type 1 diabetes
De Quervain thyroiditis
An upper respiratory infection that damages thyroid cells may cause De Quervain thyroiditis, an uncommon condition that is also called subacute granulomatous thyroiditis. It�s most common in women and often occurs during the summer and fall
.
Symptoms of de Quervain thyroiditis include:
pain in the neck, jaw, and throat
enlarged, tender thyroid gland
fever
fatigue
body pain
The condition may cause hyperthyroidism followed by hypothyroidism and last 2 to 8 weeks. Typically, thyroid function will then return to normal, though in some cases hypothyroidism may be permanent.