The thyroid, one of the smallest structures in the human body, also happens to be one of the most important. Located at the base of your neck, this organ’s substances and hormones help regulate the proper functioning of many of the other structures in the body. Specifically, the thyroid produces hormones that help control the metabolism. The most common thyroid disorders develop when this structure either produces too much of the hormone or not enough of it.

There are several diseases and disorders associated with these abnormalities. Here are the most common disorders of the thyroid.

Hyperthyroidism

This disease develops when the thyroid overacts and produces too much of its hormone. This disease is quite rare, affecting mostly women. Even so, it’s prevalence is of about 1 percent of women. This condition is most frequently caused by a coexisting Graves’ Disease, which represents around 70 percent of total cases. Another condition that causes nodules to appear on the thyroid, called toxic nodular goiter or multinodular goiter, can also disrupt the gland’s activities and cause it to produce excess hormones.

The symptoms most frequently associated with hyperthyroidism include restlessness, nervousness, anxiety, rapid palpitations, sleeping troubles, shaking and tremors, irritability, and weight loss, among others. In the case of hyperthyroidism due to Graves’ disease, the patient might also have bulging eyes.

This disease is diagnosed mostly through blood tests. Specifically, it is identified by measuring the levels of the thyroxine hormone, and the thyroid-stimulating hormone (TSH) in the blood. The latter is produced by the pituitary gland to stimulate the production of thyroxine by the thyroid. If the TSH levels are normal, but the thyroxine levels are high, it means that there is a problem with the thyroid gland.

Hypothyroidism

As its name implies, this disease is the opposite of hyperthyroidism. It is created when the thyroid is underactive and doesn’t produce enough of its hormones. This condition is caused mostly by Hashimoto’s disease, damage to the thyroid, or when this gland has been surgically removed. It is more common than hyperthyroidism, affecting around 4.6 percent of people 12 years old and older.

This condition is characterized mostly by symptoms, such as fatigue, constipation, memory problems, weakness, weight gain, slow heart rate, and even coma.

Similar to hyperthyroidism, this condition is diagnosed through the examination of the patient’s TSH and thyroxine levels in the bloodstream. A low thyroxine level despite an adequate level of TSH would indicate that the thyroid is underactive and that it is not producing enough of its hormone. Furthermore, the elevated levels of TSH suggest that the pituitary gland is producing more of the substance to compensate for the low levels of thyroxine.

Hashimoto’s Disease

Also known as chronic lymphocytic thyroiditis, this condition is the most common cause of hypothyroidism and affects around 14 million Americans. It is an autoimmune disorder where the patient’s immune system mistakenly targets and attacks their thyroid gland, disrupting its ability to produce thyroxine. However, the way it affects this structure is very subtle, and can even manifest without symptoms. Moreover, in the cases where it produces symptoms, these may resemble other diseases, which complicates identifying and treating this condition.

The most common symptoms of Hashimoto’s diseases include depression, fatigue, constipation, weight gain, thinning hair, dry skin, paleness, intolerance to cold, and the appearance of a goiter, among others.

Hashimoto’s disease is diagnosed similarly to other thyroid problems, such as through blood TSH and thyroxine levels. However, since it is an autoimmune disorder, there is also an abnormal presence of antibodies.

Graves’ Disease

This condition is very similar to Hashimoto’s disease in the fact that it is also an autoimmune disease. However, the main difference is that it causes the thyroid to overproduce hormones instead of underproducing them. It is also the most common cause of hyperthyroidism in the United States. Since it is similar to hyperthyroidism, the symptoms are the same, with the only difference being that Graves’ disease causes the patient’s eyes to bulge out slightly.

Due to the physical symptoms it creates, diagnosing Graves’ disease can be performed through a physical examination. However, the doctor’s findings are confirmed only through a blood test where he can check its TSH, thyroxine, and antibody levels. The definitive tool to diagnose Graves’ disease, however, is by administering a radioactive iodine test to check how quickly the thyroid takes up the substance. A high iodine absorption rate is consistent with Graves’ disease.

In non-autoimmune thyroid disorders, the primary cause is iodine deficiency. It can be prevented by consuming this substance in foods, which is added to table salt. For this reason, thyroid disorders are sporadic in the United States, but it could be more common in underdeveloped countries. However, when it comes to Graves’ disease, which is not preventable, the physical manifestations can be avoided by refraining from consuming excess iodine. In the cases where the person must take thyroid hormone medication, they must always adhere to the correct dosage or risk setting off their overactive thyroid.