Thyroid Disease – Types, Causes and Symptoms, and Treatments

Let’s take a closer look at some common types of thyroid diseases, along with the symptoms, causes, tests, and treatment options.

Types of Thyroid Issues

Thyroid problems are usually grouped into one of two categories: hypothyroidism or hyperthyroidism. Within these categories, there are more specific diseases, which we will discuss below.

A thyroid disorder can be influenced by issues with other glands as well. For example, the pituitary gland releases stimulating thyroid hormone (TSH), which “tells” the thyroid to work.¹ If the pituitary gland is underactive, this can also influence the thyroid gland’s activity.

Hypothyroidism (Underactive thyroid)

Hypothyroidism occurs when the thyroid is underactive. This means that the thyroid is not producing enough thyroid hormone. Hypothyroidism will cause the metabolism to slow down, causing symptoms like weight gain, cold intolerance, dry skin, and depression.

Underactive thyroid disease can be further broken down into congenital hypothyroidism, autoimmune hypothyroidism, and iatrogenic hypothyroidism.

Congenital hypothyroidism

Congenital hypothyroidism occurs when a baby has an underactive or absent thyroid gland. In most developed countries, babies’ thyroid function is checked shortly after birth since the thyroid plays an essential role in early development. Normal growth and development are still possible if congenital hypothyroidism is detected early.

Autoimmune hypothyroidism

Autoimmune hypothyroidism is also referred to as Hashimoto’s Disease. Your immune system is designed to protect you from disease and infection by releasing certain chemicals to “attack” any foreign invaders that it detects. Sometimes, the immune system functions improperly and accidentally attacks healthy body tissues. This is referred to as an autoimmune disorder. When the immune system attacks the thyroid gland, it impairs normal function of the gland.

Iatrogenic hypothyroidism

Iatrogenic hypothyroidism occurs as a result of a medical treatment that suppresses thyroid function. Sometimes, treatments meant to suppress thyroid function (in cases of hyperthyroidism) work a little too well, causing hypothyroidism. For this reason, it may take some time to figure out a proper medication regimen when treating thyroid disease.

Surgery to remove the thyroid may be recommended for thyroid disorders that do not respond to medication. For this reason, you generally have to supplement with synthetic thyroid hormones following surgery to avoid hypothyroidism.

Other causes of hypothyroidism include:

• Iodine deficiency
• Radiation therapy in the head and neck

• Pregnancy
• Treatment for hyperthyroidism

Hyperthyroidism (Overactive thyroid)

Hyperthyroidism occurs when the thyroid is overactive and too many hormones are released. When individuals suffer from hyperthyroidism, their metabolism is overactive, meaning they may experience weight loss, anxiety, and heat intolerance.

Some conditions that may cause hyperthyroidism include Graves’ disease, hyperfunctioning thyroid nodules, and thyroiditis.

Graves’ disease

Graves’ disease is a type of autoimmune thyroid disorder where the immune system attacks the thyroid gland. This, in turn, causes the thyroid to become overactive as it tries to fight back. Hyperthyroidism is commonly caused by Graves’ disease, accounting for 4 out of 5 cases of hyperthyroidism in the United States.

Hyperfunctioning thyroid nodules

Sometimes, the thyroid will develop growths called thyroid nodules. Thyroid nodules can become enlarged and produce their own thyroid hormones. These are known as “toxic adenomas” or “toxic thyroid nodules.” The most common treatments for hyperfunctioning thyroid nodules are radiation, surgery, and antithyroid medications.

Thyroiditis

Thyroiditis occurs when the thyroid becomes inflamed. This can cause abnormally high or low thyroid hormone levels. There are many different types of thyroiditis, including:

• Hashimoto’s thyroiditis
• De Quervain’s (subacute) thyroiditis
• Postpartum thyroiditis
• Silent (painless) thyroiditis

• Drug-induced thyroiditis
• Radiation-induced thyroiditis
• Acute or infectious thyroiditis

Generally, thyroiditis causes a period of hyperthyroidism followed by a period of hypothyroidism. Thyroiditis can have unique symptoms that include pain and sensitivity at the front of the neck or pain when swallowing or turning your head.

Other causes of hyperthyroidism include:

• High iodine levels
• Tumor on the pituitary gland
• Overmedication with thyroid replacement hormones

Who is at risk for thyroid issues?

Risk factors for developing thyroid issues vary depending on the condition.

Risk factors for hypothyroidism include:

• Thyroid surgery
• Family history of hypothyroidism
• Recent pregnancy or childbirth

• Smoking cigarettes or vaping nicotine products
• Having type 1 diabetes or rheumatoid arthritis

Risk factors that make you more likely to develop hyperthyroidism include:

• Family history of thyroid disease
• Having type 1 or 2 diabetes, adrenal insufficiency, or pernicious anemia
• Eating high-iodine foods or taking medications that contain high levels of iodine
• Smoking cigarettes or vaping nicotine products
• Recent pregnancy

Most common symptoms of thyroid issues

Symptoms of thyroid issues will vary depending on the type of thyroid disease.

Hyperthyroidism symptoms are associated with increased metabolism and can manifest as:

• Unexplained weight loss with an increased appetite
• Faster heart rate, heart palpitations, high blood pressure
• Excessive sweating
• Restlessness

• Frequent bowel movements
• Muscle weakness
• Hand trembling
• Lighter or shorter menstrual periods

Hypothyroidism will cause the metabolism to slow down. Common symptoms include:

• Depression
• Tiredness and fatigue
• Slower heart rate
• Sensitivity to cold
• Tingling or numbness in the hands

• Goiter (or enlargement in the neck)
• Constipation
• Dry skin and hair
• Heavy menstrual periods

Tests for thyroid issues

If you suspect you may have a thyroid disorder, your doctor will want to screen you for thyroid disease with blood tests and imaging scans. Several different tests can be ordered depending on the symptoms you are experiencing.

Thyroid blood tests

The first step in diagnosing a thyroid disorder is drawing blood to look for different levels that may indicate certain diseases. Some common thyroid blood tests include:

• Thyroid Peroxidase Antibody: Thyroid peroxidase (TPO) is usually found in the thyroid gland. This enzyme helps with normal thyroid function. A TPO antibody test looks for antibodies in the blood that attack TPO. A positive TPO antibody test helps with diagnosing an autoimmune thyroid disorder.
• Thyroglobulin Antibody: Thyroglobulin (Tg) antibody is another type of antibody that may indicate a thyroid disorder caused by an autoimmune condition. A positive thyroglobulin antibody test may indicate Hashimoto’s disease, as many people with this disease have high levels of both Tg and TPO antibodies.
• T3: T3 is one of the hormones produced by the thyroid gland. Your doctor may test your T3 levels to help diagnose a thyroid disorder. T3 is more often tested in cases of hyperthyroidism rather than hypothyroidism.
• T4: T4 is another important thyroid hormone, the main thyroid hormone that is found circulating in the blood. T4 levels are often checked alongside TSH levels to help determine the cause of thyroid issues. There are several different T4 tests your doctor may order, including a free T4 test and a T4 index.
• TSH: Thyroid stimulating hormone (TSH) is released from the pituitary gland and prompts the thyroid to release hormones. Measuring TSH levels can help determine if thyroid issues are related only to thyroid dysfunction or if there is an issue with the pituitary gland.

Thyroid imaging tests

Your doctor may also use imaging scans such as an ultrasound, thyroid scan, or radioactive iodine uptake test to look for thyroid gland function abnormalities.

An ultrasound of the thyroid is a painless imaging technique that uses sound waves to see inside the body. This will give the doctor images of your thyroid to look for abnormalities such as growths or enlargement.

Thyroid scans and radioactive iodine uptake tests are usually done together. For this test, you will take a pill that contains radioactive iodine. You may then wait for 4 to 6 hours for the iodine to build up in the thyroid. You will then be scanned to determine the location and intensity of the rays from the radioactive material. A thyroid scan will display images of the thyroid gland, showing how much of the radioactive iodine has built up and where it is located.

The thyroid gland uses iodine to make thyroid hormones, so measuring the amount of iodine that the thyroid takes up during this test helps your doctor determine if the thyroid is functioning properly.

Can you take a thyroid test at home?

If you think you may have thyroid issues, it is important to get tested to find out the cause of your symptoms. You can get your thyroid levels tested from the comfort of your own home. At-home thyroid testing involves a nurse coming to your home to draw your blood.

How are thyroid issues treated?

Hyperthyroidism treatment options

If you have hyperthyroidism, your doctor may recommend treatment with medications such as radioactive iodine, antithyroid medications, and beta blockers. Medication is usually the first line of treatment before considering surgery. If the medication does not work, then you may be advised to get your thyroid removed.

Hypothyroidism treatment options

The standard treatment for hypothyroidism is Levothyroxine. Levothyroxine is a synthetic form of thyroid hormone, which supplements the hormones that are lacking. While taking Levothyroxine (especially when you first begin treatment), your doctor will want to regularly check your TSH levels to help determine the proper dosage. If you notice any side effects such as insomnia, heart palpitations, or shakiness, you may be taking too high of a dosage.

Certain foods and medications can interfere with the proper absorption of Levothyroxine. You should avoid taking iron supplements, calcium supplements, and antacids that contain aluminum hydroxide while taking Levothyroxine. It is also best to take Levothyroxine on an empty stomach at the same time every day.

They will then send it off to a lab and contact you with the results. This type of testing offers both convenience and accuracy.

You can also do a DIY test for your thyroid health, which involves drawing your blood yourself (usually using a finger prick). The downside of at-home testing is that it is not always a very accurate method. Additionally, your doctor is unlikely to accept these test results to make a diagnosis. You should always see a healthcare provider to interpret test results rather than attempting to self-diagnose or self-treat.

Final Thoughts

If you think you may have a thyroid disorder, it is important to be proactive and find out what’s going on. Seek professional medical attention so that you can pinpoint the cause of your symptoms and find relief through proper treatment and diagnosis.