Your thyroid is a small gland in your neck that controls how fast your body uses energy

Thyroid disease means your thyroid is not working the way it should. It may produce too much of its hormone (called hyperthyroidism), too little (called hypothyroidism), or develop lumps or inflammation. When your thyroid does not work properly, it affects how your heart beats, how fast you burn calories, how warm or cold you feel, and how much energy you have.

Thyroid disease is common — millions of people have it, and many do not know it yet. The good news is that once a doctor finds it, treatment is straightforward and most people feel much better within weeks.

Key Takeaways

  • Thyroid disease happens when your thyroid gland produces too much hormone, too little, or develops physical changes like lumps or swelling.
  • The two most common types are hypothyroidism (too little hormone) and hyperthyroidism (too much hormone), and they cause opposite symptoms.
  • A simple blood test that measures thyroid-stimulating hormone (TSH) is how doctors diagnose thyroid disease.
  • Treatment depends on which type you have but usually involves either taking a daily pill or managing an overactive gland.

Hypothyroidism: When your thyroid does not make enough hormone

Hypothyroidism means your thyroid produces too little of the hormone it needs to regulate your metabolism — the process your body uses to turn food into energy. When hormone levels drop, everything slows down. Your heart rate may drop, you might gain weight even without eating more, and you may feel tired all the time.

Other signs include feeling cold when others are comfortable, dry skin, hair loss, constipation, and trouble concentrating. Some people notice their voice becomes deeper or their face looks puffy. These symptoms develop slowly, which is why many people do not realize they have hypothyroidism for months or even years.

The most common cause of hypothyroidism in the United States is Hashimoto's thyroiditis, an autoimmune condition where your immune system attacks your own thyroid cells. Other causes include iodine deficiency (rare in the US but common worldwide), certain medications, radiation to the neck, or thyroid surgery.

Hyperthyroidism: When your thyroid makes too much hormone

Hyperthyroidism is the opposite problem — your thyroid produces too much hormone, and everything speeds up. Your heart may race even when you are resting, you might lose weight without trying, and you feel jittery or anxious. Many people describe it as feeling like they have had too much coffee.

Other signs include heat intolerance, excessive sweating, trembling hands, frequent bowel movements, and trouble sleeping. Your eyes may feel irritated or look slightly bulging. Like hypothyroidism, these symptoms can develop gradually, and people sometimes mistake them for anxiety or stress.

The most common cause of hyperthyroidism is Graves' disease, another autoimmune condition where antibodies overstimulate the thyroid. Thyroiditis (inflammation of the thyroid) and toxic nodules (lumps that produce hormone on their own) are other causes.

Other thyroid conditions: Lumps, inflammation, and cancer

Beyond too much or too little hormone, your thyroid can develop physical problems. Thyroid nodules are lumps that form in the thyroid tissue. Most are benign (not cancer), but a doctor needs to check them because some are cancerous. You might feel a lump in your neck, or a doctor might find it during an exam or imaging scan done for another reason.

Thyroiditis is inflammation of the thyroid, usually caused by a viral infection or autoimmune attack. It can cause pain in the front of your neck and temporarily raise or lower hormone levels. Goiter is an enlarged thyroid that may or may not affect hormone production — it can happen with hypothyroidism, hyperthyroidism, or normal hormone levels.

Thyroid cancer is less common than nodules, but it does happen. Most thyroid cancers grow slowly and have good outcomes when caught early, especially papillary thyroid cancer, which is the most frequent type.

How doctors diagnose thyroid disease

Diagnosis starts with your medical history and a physical exam. Your doctor will ask about your symptoms, whether thyroid disease runs in your family, and whether you have had radiation or neck surgery. They will feel your neck to check if your thyroid is enlarged or has lumps.

The main test is a blood test that measures thyroid-stimulating hormone (TSH), a hormone your pituitary gland releases to tell your thyroid to make more hormone. If your thyroid is not working right, TSH levels change. High TSH usually means hypothyroidism; low TSH usually means hyperthyroidism. Your doctor may also measure the actual thyroid hormones themselves, called T3 and T4.

If your doctor finds a nodule or suspects thyroid cancer, they may order an ultrasound, which uses sound waves to create a picture of your thyroid. Sometimes a fine-needle biopsy is needed — a thin needle removes a tiny sample of tissue to check under a microscope. These tests are quick and cause minimal discomfort.

What happens after diagnosis

Treatment depends on which type of thyroid disease you have. For hypothyroidism, the standard treatment is a daily pill containing synthetic thyroid hormone (usually levothyroxine). Your doctor starts with a dose and checks your blood levels after six to eight weeks to adjust if needed. Most people find the right dose within a few months and feel significantly better.

For hyperthyroidism, options include antithyroid medications that block hormone production, radioactive iodine that destroys thyroid cells, or surgery to remove part or all of the thyroid. Your doctor will discuss which approach fits your situation based on the cause, your age, and other health conditions.

For nodules, treatment depends on whether they are cancer and how fast they are growing. Many benign nodules need only monitoring with ultrasound every year or two. Cancerous nodules usually require surgery and sometimes radioactive iodine treatment afterward.

Living with thyroid disease

Once you start treatment, most people with thyroid disease live completely normal lives. You will need regular blood tests — usually once a year after your dose is stable — to make sure your treatment is still working. If you take levothyroxine for hypothyroidism, take it on an empty stomach in the morning, as food and certain medications can interfere with how your body absorbs it.

Tell your doctor about any new symptoms, and mention your thyroid disease when starting new medications, because some drugs interact with thyroid treatment. Pregnancy, menopause, and aging can all change how much thyroid hormone you need, so your dose may need adjustment at different life stages.

Many people with thyroid disease also benefit from connecting with others who have the same condition. Online communities and support groups exist for both hypothyroidism and hyperthyroidism, and they can answer questions about daily life with the disease.

Frequently Asked Questions

Can thyroid disease go away on its own?

Hypothyroidism from Hashimoto's disease is permanent and requires lifelong treatment. Hyperthyroidism from Graves' disease sometimes goes into remission, especially with antithyroid medication, but many people eventually need radioactive iodine or surgery. Thyroiditis from a viral infection may resolve on its own, but your doctor needs to monitor you during recovery.

Will I need surgery for thyroid disease?

Most people with hypothyroidism never need surgery — medication alone works well. Surgery is more common for hyperthyroidism if medication does not work or you cannot tolerate it, and for thyroid cancer or large nodules causing problems. Your doctor will discuss whether surgery is necessary for your specific situation.

Does thyroid disease run in families?

Yes, autoimmune thyroid diseases like Hashimoto's and Graves' disease tend to run in families. If a close relative has thyroid disease, your risk is higher, but having the gene does not mean you will definitely develop it. Tell your doctor about your family history so they can watch for early signs.

Can I get thyroid disease at any age?

Thyroid disease can develop at any age, from childhood to old age. Hypothyroidism is more common as people get older, while Graves' disease often appears in younger adults and middle age. Thyroid cancer can occur at any age but is more common in people over 30.

What should I eat if I have thyroid disease?

There is no special thyroid disease diet, but certain foods can affect how your body absorbs thyroid medication. If you take levothyroxine, avoid taking it with calcium, iron, or soy products within four hours. Otherwise, eat a balanced diet with adequate iodine, selenium, and zinc — nutrients your thyroid needs to function.