Hyperthyroidism

Hyperthyroidism develops when the butterfly-shaped gland in the neck called the thyroid is too active and produces an excess of hormones. These hormones help regulate the body’s metabolism, energy levels, temperature, and other functions.

Hyperthyroidism, often referred to as an overactive thyroid, can often be difficult to diagnose at first because some of its symptoms – like weight loss, fatigue, and a fast or irregular heartbeat – are similar to those of several other health problems. 

Hyperthyroidism Symptoms

The potential symptoms of hyperthyroidism may include: 

• Unexplained weight loss.
• Fast or irregular heart rate.
• Nervousness and anxiety.
• Increased appetite and hunger.
• Feelings of fatigue, or tiredness. 
• Sensitivity to heat.
• Trembling in the hands and fingers.
• More frequent bowel movements.
• Muscle weakness.
• Sweating.
• Thin skin and brittle hair.
• Sleep problems.

How Is Hyperthyroidism Diagnosed?

To determine whether you have hyperthyroidism, your doctor will first review your medical history and give you a physical exam that would include gently feeling you neck to see whether your thyroid gland is enlarged, bumpy, or tender.

A blood test is the primary way for your doctor to determine whether your thyroid is working properly. The test measures the level of three main thyroid hormones in your blood – thyroid stimulating hormone (TSH), free triiodothyronine (T3), and free thyroxine (T4). In hyperthyroidism, free T3 and free T4 levels are often elevated and TSH levels are lower than normal.

In addition to blood tests, your doctor may recommend imaging tests to determine whether you have hyperthyroidism. These imaging tests may include:

• Radioactive iodine uptake and scan – While performed as one test the uptake measures the amount of iodine absorbed by the thyroid after you take an oral dose of radioactive iodine while the scan identifies the areas of the thyroid which are over or under active. 
• Thyroid ultrasound – although performed less frequently in individuals with hyperthyroidism, a thyroid ultrasound may be ordered to see if there are any nodules on your thyroid gland 

Hyperthyroidism Causes

The potential causes of hyperthyroidism include:

• Graves' disease: This autoimmune disorder overstimulates the thyroid, leading it to overproduce the hormones needed by the body. The most common cause of hyperthyroidism, Graves’ disease is most often found in young to middle-aged women and tends to be hereditary (run in families).
• Nodules on the thyroid: These lumps on the thyroid gland may become more active and produce more hormones that what is needed. These nodules are not usually cancerous. 
• Thyroiditis: Inflammation of the thyroid gland that temporarily causes the gland to be overactive. The causes of thyroiditis are varied and can include viral infection to postpartum thyroiditis which develops within a year after a woman gives birth.
• Too much iodine: Your thyroid uses iodine to create hormones. Whether consumed through your diet or medications, an excess of iodine in the body may cause your thyroid to produce more hormones than your body needs. 

Hyperthyroidism vs. Hypothyroidism

Both hyperthyroidism and hypothyroidism are conditions that affect the amount of hormones the thyroid gland produces to help manage different functions in the body. 

In hyperthyroidism, the thyroid is overactive (“hyper”) and produces an excess of the hormones your body needs, whereas with hypothyroidism, the thyroid is underactive and does not produce enough of the hormones needed. Each condition has different symptoms, causes, and treatments. 

Hyperthyroidism Treatment Options

There a several treatments available to manage an overactive thyroid. Your doctor will work with you to develop a treatment plan based on your unique needs, the underlying cause of your condition, and the severity of your symptoms. Occasionally a thyroid condition which is mild and expected to resolve will not require therapy. The possible treatments for hyperthyroidism include: 

• Antithyroid medicines like propylthiouracil or methimazole to reduce or block the effects of the excess hormones produced by the thyroid 
• Radioactive iodine therapy (taken in pill or liquid form) to destroy the overactive thyroid and stop the excess production of hormones
• Beta blockers, which are also used to treat high blood pressure, to help manage some of the symptoms of hyperthyroidism, like heart palpitations and rapid heartbeat. Beta blockers do not affect the production of hormones by the thyroid.
• Surgery (thyroidectomy) to remove part or all of the thyroid
• Steroids to control inflammation of the thyroid

Is Hyperthyroidism Curable? 

Hyperthyroidism is a treatable and manageable condition. Depending on the cause of hyperthyroidism, the condition may resolve (or go into remission) with treatment. In some cases, hyperthyroidism that has gone into remission may recur later. Those who are living with Graves’ disease may experience a worsening of their hyperthyroidism over time.

Hyperthyroidism can be cured only through the surgical removal of the thyroid gland or the destruction of the gland through treatments like radioactive iodine therapy. Those who have their thyroid gland removed or destroyed will need to take thyroid hormone replacement medications daily for the rest of their lives. 

Untreated Hyperthyroidism

If you are living with hyperthyroidism, it is important to have your condition monitored regularly by your doctor. Untreated or undertreated hyperthyroidism can lead to a number of potential and serious complications, including: 

• Thyroid crisis, or thyroid storm – a rare a life-threatening complication
• Heart problems like irregular heartbeat or atrial fibrillation
• Elevated blood pressure
• Osteoporosis (weak and brittle bones)
• Pregnancy-related complications like miscarriage and preeclampsia 

When to Contact a Doctor

Talk to your doctor about being tested for hyperthyroidism if you are experiencing other potential signs of the condition. If you have been diagnosed with hyperthyroidism, contact your doctor or seek immediate medical attention at the nearest Emergency Department if you are experiencing any of the following signs of thyroid crisis:

• High fever.
• Rapid heart rate.

FAQ

Who is at risk for hyperthyroidism? 

Your chances of developing hyperthyroidism are greater if you are:

• Female.
• Have a personal or family history of thyroid problems.
• You are pregnant or had a baby in the last six months. 

Can hyperthyroidism cause female infertility? 

Hyperthyroidism may cause temporary infertility in women who wish to become pregnant, although the infertility often resolves once the thyroid hormones are back to normal, healthy levels. A woman who is living with hyperthyroidism may become pregnant. A woman with hyperthyroidism who desires pregnancy should work with her physician to bring thyroid blood tests into an optimal range for a healthy pregnancy. More frequent monitoring of thyroid function is performed over the course of the pregnancy as adjustment of therapy is often required. 

Can I develop hyperthyroidism during pregnancy? 

Hyperthyroidism may develop during pregnancy and is usually caused by Graves’ disease. 

Can children develop hyperthyroidism? 

Hyperthyroidism in children and adolescents is rare. Through medication, those children diagnosed with the condition can full and active lives. 

What foods should you eat if you have hyperthyroidism?

No specific diet has been linked to hyperthyroidism.