Your thyroid is arguably one of the most important parts of your body. As part of the endocrine system, this small gland in your neck secretes thyroid hormone, which is responsible for directing all of your metabolic functions-that means controlling everything from digestion to mood to energy.
When the thyroid malfunctions, it can affect every facet of your health. Unfortunately, thyroid problems are common, especially in women. According to the American Thyroid Association, one in eight women will develop a thyroid disorder during her lifetime. It can happen at any age, but “problems frequently develop in the 20s and 30s, especially in women,” Jason C. Baker, M.D., endocrinologist at Weill Cornell Medicine and New York-Presbyterian, tells SELF.
Although they’re common, up to 60 percent of people with a thyroid disorder don’t know they have one, which is why it’s important to be aware of what these conditions are and how they present themselves.
These are all the most common thyroid disorders and what we know (and don’t know) about the causes of each. If you think you may have one of the conditions below, voice your concerns to your doctor so you can be appropriately screened and get your condition under control.
Hypothyroidism is also referred to as underactive thyroid. In this situation, your thyroid doesn’t make enough of the thyroid hormone, therefore, all of your body’s important processes get slowed down. Weight gain, decreased appetite, fatigue, dry skin, and heavy periods are all hallmark symptoms of hypothyroidism, as your body’s cells are unable to work at their normal level of efficiency.
The most common cause of an underactive thyroid is thyroiditis, swelling of the thyroid gland (see below), according to the National Institutes of Health.
“Thyroiditis is essentially thyroid inflammation,” Baker says. Thyroiditis can cause pain in the thyroid, or lead it to produce too much or too little thyroid hormone. Some may start to develop symptoms over time, after the inflammation has been impacting the thyroid for a while. The most common cause of thyroiditis is an autoimmune disease, which causes the immune system to mistakenly send antibodies to attack the thyroid gland. The specific one most frequently associated with thyroiditis (and that then causes hypothyroidism) is called Hashimoto’s disease. Hashimoto’s is more common in women, Baker says, and it tends to be inherited. Having another autoimmune disease can also increase your chances of developing Hashimoto’s.
Within the first year after childbirth, some women may develop postpartum thyroiditis that lasts anywhere from a few weeks up to a few months. The inflammation can cause a period of hyperthyroidism followed by period of hypothyroidism, or for some, just one or the other. For most women, the condition is transient, Baker explains, clearing up in a year or so. “But sometimes it can be permanent.” The exact cause isn’t clear, but according to the Mayo Clinic, it is believed that women who develop postpartum thyroiditis actually have an underlying autoimmune disorder before pregnancy that flares up after giving birth.
Having a viral or bacterial infection can also cause antibodies to attack the thyroid, similarly to Hashimoto’s. Some medications, like the heart medication amiodarone, can also cause thyroiditis.
The most common cause of hyperthyroidism is an autoimmune disease called Graves disease, where the body attacks the thyroid and causes it to overproduce thyroid hormones. Postpartum thyroiditis can also cause hyperthyroidism, as can thyroiditis caused by an infection in the body.
4. Thyroid nodules
A nodule is simply an abnormal growth of cells, which can be either solid or fluid-filled. “Thyroid nodules are quite common,” Baker says. Most are benign, he adds, and present without symptoms. The only way you’ll know you have it is if you notice a lump in your neck or it gets picked up during a routine health exam or scan. Sometimes nodules can cause the thyroid to become overactive, but “in the majority of cases, they’re not related to under- or overactive thyroid,” Baker says.
However, some thyroid nodules can be cancerous. If you notice any lumps or swelling of your thyroid, you should always get it checked out to rule out cancer.
“Goiter is simply a catch-all name for an enlarged thyroid,” Baker says. Both hyper- and hypothyroidism can cause the thyroid to swell. Several nodules clumped together can also cause a goiter, as can thyroiditis, thyroid cancer, and even hormonal fluctuations during pregnancy. Goiters can also form if you have an iodine deficiency, but this isn’t a problem that we really see anymore in the U.S.
A goiter that isn’t large enough to impact swallowing or breathing is nothing to worry about, but knowing what caused it to form is important to get to the bottom of any other thyroid problems you have.
6. Thyroid cancer
According to the National Cancer Institute, there were an estimated 62,450 new cases of thyroid cancer in 2014. The rate has been increasing in recent years, which experts estimate is partly because new technologies have made it easier to detect. The full reason for this increase, though, is not yet known. The good news is that thyroid cancer is usually very treatable, and the survival rates are high.
Thyroid cancer often presents without symptoms and just causes a goiter or nodules that usually will not impact the thyroid’s function or cause any pain in the early stages. As it progresses and cancerous nodules grow, you may experience pain in the neck, difficulty swallowing, or a hoarse voice.