- An overactive thyroid, or hyperthyroidism, has symptoms like fatigue, anxiety, and weight loss.
- Some things that can cause hyperthyroidism include Grave's disease and thyroiditis.
- If you don't treat hyperthyroidism, it increases risk of complications like stroke and heart failure.
- Visit Insider's Health Reference library for more advice.
An overactive thyroid (hyperthyroidism) is relatively rare, affecting just 1% of people in the US.
It occurs when your thyroid glands produce too much of a hormone called thyroxine. These thyroid hormones control how your body uses energy, so they affect almost every organ, even how quickly your heart beats.
An overactive thyroid can accelerate your body's energy consumption, speeding up your metabolism and nearly every organ in your body. Just like drinking too much coffee might cause you to feel wired or anxious due to an increased heart rate, an overactive thyroid can result in symptoms like nervousness, heart racing, and trembling.
Hyperthyroidism symptoms vary from person to person, making it tricky to identify. Here are a few signs worth watching for.
Adults with an overactive thyroid typically see symptoms pop up suddenly, while signs may show differently in older populations.
"Younger patients usually present with a quick onset of symptoms. Sometimes in the elderly, symptoms may be very mild and harder to spot," says Juan Jaume, MD, professor of medicine at the University of Toledo.
Common symptoms in adults include:
- Shaky hands
- Muscle weakness
- Trouble sleeping
- Vision changes
- Menstrual changes
- Hair loss or brittle hair
- Thin skin that is warm and moist to the touch
- Heart palpitations
Common symptoms in the elderly include:
- Atrial fibrillation (rapid or irregular heartbeat)
- Weight loss (often despite an increased appetite)
- Cognitive decline
- Muscle shakes or tremors
- Sweating or trouble tolerating heat
- Shortness of breath
- Goiter (enlarged thyroid gland below your Adam's apple)
Elderly populations are also more likely to show symptoms that are "non-specific," like muscle weakness, persistent vomiting, hypercalcemia (too much calcium), or worsening osteoporosis. However, any of the above symptoms can occur at any age.
While there is no single cause for hyperthyroidism, there are a few major reasons your body might be producing too much thyroxine, the thyroid hormone.
Graves' disease is an autoimmune condition and the most common cause of hyperthyroidism in the United States.
You're more likely to develop Graves' disease if you are:
- Over 30
- Diagnosed with another autoimmune disorder like vitiligo, diabetes, or rheumatoid arthritis
- Pregnant or recently gave birth
- Using nicotine
Graves' disease often runs in the family. Ask your loved ones if anyone has a Graves' diagnosis and share any cases with your doctor, as this increases your risk of developing the disorder.
Hyperfunctioning thyroid nodules
A thyroid nodule is an unusual lump of thyroid cells that develop in your thyroid gland, just below the Adam's apple. If the thyroid starts to grow larger in adulthood, nodules may form. Overactive thyroid nodules are often responsible for hyperthyroidism.
Common risk factors for developing hyperfunctioning thyroid nodules include:
- Radiation exposure to your head or neck from medical treatments
- Being female
- Having immediate family with thyroid nodules
- Having immediate family with endocrine cancers like thyroid cancer
Thyroiditis is swelling, or inflammation, of your thyroid gland. This condition may leave your neck or throat tender or painful to the touch. However, this condition may also be painless, making it difficult to spot.
Thyroiditis is often followed by hypothyroidism (the opposite of hyperthyroidism). This means your body could switch from making too many thyroid hormones to too few.
Thyroiditis is often caused by:
- Hashimoto's disease, an autoimmune disease where your immune system attacks your thyroid
- Postpartum thyroiditis, beginning less than a year after giving birth
- Subacute thyroiditis, triggered by an infection and resulting in pain in your neck
- Certain medications, including lithium, interferon, or checkpoint inhibitors
Hyperthyroidism doesn't typically go away on its own, so it's important to seek help from your doctor. Starting treatment as soon as possible increases your odds of a safe and effective recovery that will prevent long-term health issues.
"Although Graves' Disease might go into remission sometimes, you need to see a doctor for the correct diagnosis and proper management of your condition," says Jaume.
Your provider will first use thyroid blood tests and imaging tests to confirm that hyperthyroidism is causing your symptoms. After diagnosis, your provider may recommend a treatment based on your age, medication allergies, and conditions like pregnancy or heart disease. Your doctor will also consider possible side effects and your own preferences before selecting a treatment.
Hyperthyroidism is usually treated via medication or radioiodine therapy. Beta-blockers, antithyroid medications, and ancillary agents like anti-inflammatories can all help.
Thyroid surgery to remove your thyroid gland is another treatment option. However, this is generally considered as a last resort.
"Removal of the thyroid gland typically causes hypothyroidism, requiring you to take thyroid supplements for the rest of your life," says Bradley Katz, MD, and professor of neurology at the University of Utah.
Without treatment, hyperthyroidism can have serious long-term effects on your health.
"Untreated hyperthyroidism can develop into serious medical conditions such as heart and bone issues and thyroid storm," says Katz. A thyroid storm, also called a thyrotoxic crisis, is a rare but life-threatening complication of hyperthyroidism that can cause symptoms like seizures, delirium, coma, and cardiac arrest.
One in three people with hyperthyroidism caused by Graves' disease experience eye problems, which makes timely treatment critical for your eyesight. Vision loss is also a risk in roughly one in every twenty to thirty cases.
Complications of hyperthyroidism may include:
- Thyroid storm
- Vision loss
- Heart failure
- Osteoporosis (weak and brittle bones)
- Pregnancy issues including miscarriage
- Blood clots
- Fertility problems
"Hyperthyroidism can come at any age. Older people may have less obvious symptoms or even no symptoms," says Katz.
Since there is no single age, cause, or identifying symptom for hyperthyroidism, it can be hard to diagnose on your own.
Sharing your symptoms with your doctor early on reduces your risk of medical complications and helps you get back to living a happier, healthier life.