How Do You Feel When You Have Hyperthyroidism?

Hyperthyroidism, also referred to as overactive thyroid, is a condition where your thyroid gland creates more thyroid hormone than your body needs.

Around 1%¹ of people aged 12 and above have hyperthyroidism.

Thyroid hormones help regulate the way your body uses energy, so they affect almost every organ, including your heart. When you have too much thyroid hormone, it speeds up body functions and causes symptoms.

The condition affects everyone differently and varies in severity, but how does it feel to have hyperthyroidism?

Signs and symptoms of hyperthyroidism

Your thyroid controls your body’s metabolism (the rate it burns energy). Many body functions speed up when too much thyroid hormone is released into your bloodstream, which causes symptoms and changes to the way you feel. These may include:

• Irritability

• Shaky hands

• Racing heart

• Increased sweating and heat intolerance

• Trouble sleeping

• Anxiety

• Muscle weakness

• Fine, brittle hair

• Thinning of the skin

• Unexplained weight loss

• Hoarse voice

• Difficulty concentrating

• Exercise intolerance

• Chest pain

• Breathlessness

• Frequent bowel movements, sometimes diarrhea

You may lose weight even if your appetite is normal or increased because your body is burning energy at a fast rate. At first, you might feel energetic, but as the condition continues, your body may start to wear down, leaving you feeling tired.

Hyperthyroidism typically starts off slowly, but changes can be sudden in some young people.

You might associate your symptoms with other causes or life changes; for example, you might think your irritability or shaky hands are caused by stress. If you're dieting and trying to lose weight, you might think you’re seeing results.

Keep an eye on your symptoms and talk to your doctor about any that continue or start to affect your daily life.

Hyperthyroidism complications

You may experience other complications as the condition progresses, including:

• Goiter (swelling of the thyroid gland in your neck)

• Missed or irregular periods

• Fertility problems

• Atrial fibrillation (fast and irregular heartbeat, which may have no symptoms)

• Erectile dysfunction

• Breast tissue growth in men

• Pregnancy complications (premature birth, pre-eclampsia, miscarriage)

• Eye and vision problems (double vision, eye irritation, bulging eyes)

• Thyroid storm (an abrupt and life-threatening symptom flare-up)

• Osteoporosis and bone fractures

Thyroid storm

Thyroid storm is a life-threatening condition that can happen when hyperthyroidism gets dramatically worse. It can be triggered by infection, emotional stress, severe burns, or surgery.

The most common cause of thyroid storm is when people suddenly stop taking hyperthyroidism medication.

Thyroid storm symptoms are similar to hyperthyroidism symptoms, but they may be exaggerated.

Thyroid storm symptoms include:

• Fever

• Very rapid heart rate

• Abnormal heart rhythm

• Loss of appetite and rapid weight loss

• Fear and a sense of doom

• Confusion

• Agitation

• Abdominal pain

• Dehydration

• Shock

Causes of hyperthyroidism

Hyperthyroidism is caused by an enlarged thyroid gland in some cases, but the most common cause is Graves’ disease.

The condition can also be caused by medications and iodine-related thyroid dysfunction. 80%² of people who live in an iodine-sufficient area have Graves’ disease, which causes hyperthyroidism.

What are the risk factors for hyperthyroidism?

Hyperthyroidism occurs more often in women and people over the age of 60.¹

You have a greater risk of developing hyperthyroidism if you:

• Use nicotine products

• Consume excessive amounts of iodine-rich foods, such as kelp

• Have type 1 or 2 diabetes

• Have a family history of thyroid disease

• Use medications containing iodine

• Were pregnant within the last six months

• Have primary adrenal insufficiency (a hormone disorder)

• Have pernicious anemia (a disorder caused by a vitamin B12 deficiency)

How is hyperthyroidism treated?

Most hyperthyroidism cases are treatable, and your thyroid hormone levels will return to normal.

Treatment will help prevent complications and long-term health issues. It will also ease uncomfortable symptoms and make daily life easier.

There is no one-size-fits-all hyperthyroidism treatment. Your treatment plan will depend on the cause of your hyperthyroidism and its severity.

Your doctor will consider:

• Any potential allergies

• Your age

• Side effects of medications

• If you have access to a thyroid surgeon

Primary hyperthyroidism treatments include:

Medication

Hyperthyroidism medication lessens your symptoms by stopping your thyroid from making too much hormone.

Common anti-thyroid medications include:

• Methimazole (Tapazole)

• Propylthiouracil (PTU)

In rare cases, PTU can cause liver damage, so methimazole is usually preferred. However, PTU is safer for use during pregnancy.

These medications slow thyroid hormone production, helping to control hyperthyroidism. It may take a few months for these medications to return your thyroid hormone levels to normal. Some people have hyperthyroidism remission after taking these medications, but it is usually only temporary.

Beta-blockers are another hyperthyroidism medication, but they only treat hyperthyroidism symptoms and don’t affect the thyroid gland. Your doctor may prescribe beta-blockers right after diagnosis to reduce your symptoms, such as anxiety, tremors, and rapid heart rate.

You can take beta-blockers with other types of treatment. Once your thyroid levels return to normal, your symptoms will ease, and your doctor may recommend you stop taking them.

Radioactive iodine

This treatment is taken orally by pill or liquid in a very controlled setting.

The radioactive iodine enters your bloodstream and destroys the overactive thyroid cells, reducing your body’s thyroid hormone production. Your symptoms should ease in a few months.

This treatment causes hypothyroidism (underactive thyroid), which you can manage with thyroid supplements.

Radioactive iodine has been used for many years safely, despite concerns about radioactive material. Most adults in the US with hyperthyroidism receive radioactive iodine treatment because it’s so effective. However, this treatment isn’t suitable for women who are breastfeeding or pregnant.

Surgery

A thyroidectomy is a procedure where most of your thyroid gland is removed. It is most commonly recommended for women planning a pregnancy or when medical professionals suspect a malignancy.

Hypothyroidism usually follows a thyroidectomy, and your doctor will prescribe thyroid supplements to return your hormone levels to normal.

You should discuss the benefits and drawbacks of each treatment with your doctor. You’ll typically see an endocrinologist (a specialist in hormone conditions) to set up the best treatment plan for you.

When to speak to a doctor

Talk to your doctor if you’re experiencing hyperthyroidism symptoms. They will ask you about your symptoms and how long you have had them. If they suspect you have a thyroid issue, they'll carry out a blood test to check your thyroid function.

If the blood work shows you have an overactive thyroid, your doctor can order additional tests to identify the cause.

People with hyperthyroidism can develop hypothyroidism. Speak to your doctor if you develop symptoms of hypothyroidism while receiving hyperthyroidism treatment.

Hypothyroidism symptoms include:

• Physical and mental sluggishness and fatigue

• Cold intolerance

• Depression

• Constipation

• Unexplained weight gain

Call 911 or go to the emergency department if you experience dizziness, a change in consciousness, an irregular, rapid heartbeat, or any symptoms of thyroid storm.

The lowdown

The outlook for hyperthyroidism will depend on what’s causing it. The cause of your hyperthyroidism may go away on its own without treatment, but Graves’ disease can worsen over time when left untreated.

Hyperthyroidism complications can impact your quality of life, and some, like thyroid storm, can be life-threatening.

The long-term outlook for hyperthyroidism improves with early diagnosis and treatment, so speak to your doctor if you have any symptoms.