What Is Hyperthyroidism?
Hyperthyroidism is when your thyroid -- the butterfly-shaped gland at the bottom of your neck, just above your collarbone -- makes too much thyroid hormone. Because your body relies on precise levels of this substance to function properly, an excess throws off your entire system. It's common to notice its effects, which may include changes to your hair, eyesight, heart rate, mood, and weight.
An overactive thyroid usually can't correct itself without help. You'll need to treat it with medication and, in some cases, surgery.
Hyperthyroidism vs. Hypothyroidism
Although these two health conditions sound alike, they're opposites.
Hyperthyroidism means that your thyroid is making too much hormone.
Hypothyroidism means that your thyroid isn't making enough hormones.
Hyperthyroidism and hypothyroidism can cause different symptoms and require different treatments.
Thyroid Function
What we call thyroid hormone actually includes two different hormones: thyroxine (T-4) and triiodothyronine (T-3). Together, these chemicals impact every cell in your body and how your body functions.
For instance, thyroid hormone controls how fast your heart beats and how quickly food moves through your digestive tract. It controls your metabolism (all the things your body does to turn food into energy and keep you going). It affects your central nervous system and even helps keep your skin and hair healthy.
Hyperthyroidism Symptoms
Because hyperthyroidism can speed up your metabolism, it can cause some uncomfortable symptoms. Common signs include:
- Feeling nervous or anxious
- Feeling cranky
- Mood swings
- Having more or less energy than usual
- Trouble swallowing
- A swollen thyroid, called a goiter (you might see swelling at the base of your neck)
- Losing weight suddenly, without trying
- Fast or uneven heartbeat or palpitations (pounding in your heart)
- Having more bowel movements (pooping) than usual
- Increased hunger
- Sweating
- Muscle weakness
- Shaking in your hands and fingers (tremor)
- Insomnia (trouble falling or staying asleep)
- Thinning skin
- Hair breakage or loss
- Changes in your period (for instance, it could be lighter than usual or happen less often)
- Eye pain
When you first get hyperthyroidism, you may feel energetic. This is because your metabolism is sped up. But over time, this increase in your metabolism can break your body down and make you feel tired.
If you’re an older adult, you’re more likely to have subtle symptoms such as a faster heart rate or being more sensitive to warm temperatures.
Certain medicines can mask the signs of hyperthyroidism. If you take beta-blockers to treat high blood pressure or another condition, you might not know you have an issue. Be sure your doctor knows about all the medications you take.
Hyperthyroidism Causes
Several health issues can cause hyperthyroidism, including:
Graves’ disease. This immune system condition is the most common reason for hyperthyroidism. Normally, your immune system goes after bacteria and viruses that get inside your body. But if you have Graves’ disease, it turns on your thyroid instead. This causes the gland to make too much thyroid hormone.
Doctors aren’t sure why some people get Graves’ disease, but it tends to run in families. It’s also more likely to affect people assigned female at birth (AFAB) who are under the age of 40.
Thyroid nodules (Plummer’s disease). These lumps of tissue in your thyroid can become overactive, making too much thyroid hormone. Plummer’s disease is more common in older people.
Thyroiditis. If your thyroid becomes inflamed, it can start to leak hormones into your bloodstream. This is often followed by hypothyroidism, in which your thyroid doesn’t make enough hormones.
Thyroiditis can happen:
- After pregnancy
- When you get a virus or have another issue with your immune system
- If you take too much thyroid medication
You can also get hyperthyroidism if you get lots of iodine in a medication or supplement. That's because your thyroid uses iodine to help make thyroid hormone.
Thyroid Eye Disease
About 30% of people with Graves’ disease get a condition called thyroid eye disease (TED). It affects how well you can see and the structure of your eyes, including the muscles and tissues around them. TED symptoms include:
- Bulging eyes
- A gritty feeling in your eyes
- Eye pain
- Eye pressure
- Redness or inflammation in or around your eyes
- Eyelids that are puffy or pulled back
- Sensitivity to light
- Double vision
- Loss of vision
You can have TED even if you haven't been diagnosed with Graves' disease. If you notice any changes in your vision, have your eyes checked.
Hyperthyroidism Diagnosis
Your doctor will ask about your health history and look for symptoms such as a swollen thyroid, fast pulse, moist skin, and shaking in your hands or fingers. They'll order tests that might include:
Thyroid panel. This blood test measures the levels of thyroid hormone and thyroid-stimulating hormone (TSH).
Thyroid scan. A technician injects a small amount of radioactive iodine into your bloodstream. Your thyroid absorbs it, and a special camera takes pictures of the gland to look for nodules or other issues.
Ultrasound. A device called a transducer uses sound waves to create images of your thyroid.
Radioactive iodine uptake test. You swallow a tiny, safe amount of radioactive iodine. Then, a device called a gamma probe measures how much of the iodine collects in your thyroid. If this uptake is high, you probably have Graves’ disease or thyroid nodules.
Hyperthyroidism Risk Factors
You're more likely to have hyperthyroidism if any of the following apply to you:
- You're AFAB
- You're 40-60 years old
- Hyperthyroidism runs in your family
- You have a lot of iodine in your diet, either in the food you eat or supplements you take
- You're pregnant
Certain ongoing health issues can also put you at risk, including:
- Type 1 diabetes
- Addison's disease
- Pernicious anemia
Hyperthyroidism Treatment
Treating an overactive thyroid means lowering your levels of thyroid hormone. Your doctor will help you choose a treatment based on your age, overall health, the reason for your hyperthyroidism, and your symptoms.
Your options might include:
Radioactive iodine. This is the most common way to treat hyperthyroidism. You swallow a tiny, safe amount of radioactive iodine. Your overactive thyroid cells absorb it and die. This makes your thyroid shrink, lowering your thyroid hormone levels, although your symptoms may not improve for several months.
Taking this medication may also cause hypothyroidism, but that's easier to treat than hyperthyroidism -- you’ll take a hormone supplement once a day.
Surgery. If medications aren’t a good option for you, your doctor may remove all or part of your thyroid. This is called a thyroidectomy. Afterward, you'll need to take a daily pill that provides the right amount of thyroid hormone that your body needs to stay healthy.
While this surgery works well, it does come with some risks. It can damage your vocal cords and your parathyroid glands. Those are two pea-sized glands that sit next to your thyroid and help regulate the amount of calcium in your blood.
Hyperthyroidism medication
Anti-thyroid drugsblock your thyroid from making too many hormones. You may see your symptoms improve within a few months, although you'll probably need to keep taking medication for at least a year. This type of treatment can be a useful, safe option if you're pregnant, thinking about becoming pregnant, or nursing.
Beta-blockers. These medications are usually used to treat high blood pressure. They can't reduce high levels of thyroid hormone, but they can help with how high levels make you feel. For instance, beta-blockers can lessen symptoms such as anxiety, shaking, or a fast heartbeat.
Hyperthyroidism in Pregnancy
Too much thyroid hormone can make it hard for you to get pregnant. An overactive thyroid could also cause complications for you as well as your baby during pregnancy.
Severe morning sickness can sometimes cause hyperthyroidism. This is often a short-term condition.
If your thyroid levels are only slightly higher than usual and your symptoms are mild, your doctor may hold off on treatment and do monthly blood tests to monitor you. If your thyroid hormone levels become a concern, a low dose of anti-thyroid medication is usually the next step.
If you are allergic to anti-thyroid medication and can't take it, you may opt for surgery to remove part or all of your thyroid. This is safest during your second trimester.
Hyperthyroidism Prevention
You can't prevent hyperthyroidism. But knowing you're at risk can help you and your doctor keep a close eye on your health. If symptoms arise, you'll be able to spot them and start treatment right away.
Treatments for Eye Problems
If you have thyroid eye disease but your symptoms aren’t severe, you can usually manage them by:
- Avoiding bright lights
- Protecting your eyes in windy weather
- Raising the head of your bed
- Using eye drops
Your doctor may also suggest a selenium supplement. Although more research needs to be done, some studies show that this mineral can improve thyroid function.
In some cases, your doctor might prescribe a medication called teprotumumab-trbw (Tepezza). It’s FDA-approved to treat the symptoms of thyroid eye disease. They might also suggest steroids or other medications to help control any swelling behind your eyes.
If your thyroid eye disease is severe, surgery may be the best option. There are two surgery options:
Orbital decompression surgery. It involves removing the bone between your sinuses and eye socket. It can make more room for your eyes so that they go back to their normal position. It can help improve your vision. There are risks to this surgery, including double vision.
Eye muscle surgery. Sometimes used to correct double vision, this surgery involves cutting eye muscles that are covered in scar tissue because of thyroid eye disease. The cut muscles are then reattached in a different position, which puts your eyes back in proper alignment. You may need this surgery more than once to get the best results.
Hyperthyroidism Complications
If left untreated, an overactive thyroid can cause:
- Skin rashes
- Muscle weakness
- Heart issues, including heart failure
- Blood clots
- Trouble getting pregnant
- Osteoporosis (thin, easily broken bones)
- Stroke
Thyrotoxic crisis
If your thyroid releases a lot of hormones in a short time, it can cause severe symptoms that may be life-threatening. This is sometimes called a thyroid storm. If you have any of these symptoms, get to a hospital right away:
- High fever (104 F or more)
- Very fast heart rate (over 140 beats/minute)
- Delirium (feeling confused or not understanding what's going on around you)
Living With Hyperthyroidism
Once you begin treatment, try to:
Take your medication exactly as prescribed. If you have questions, ask your doctor or pharmacist.
Get moving. Regular exercise can improve your outlook as well as your health.
Keep your doctor appointments. That will help them understand how you're doing and adjust your treatment if they need to.
Start a journal. Jot down the symptoms you have and what seems to make them better or worse. Then, let your doctor know.
Lower your stress. You can't get rid of it for good, but you can get better at how you respond to it. If you're not sure how, ask your doctor to suggest some relaxation techniques.
Talk with others. After you begin treatment, it could take a while before you feel like yourself again. Let your loved ones know, so they can support you. A counselor or therapist can also help you find new ways to deal with the process.
Hyperthyroidism Diet
Eating healthy foods doesn't just benefit your thyroid. It's also good for your heart, lungs, and other parts of your body.
Foods to eat with hyperthyroidism
Opt for a variety of:
- Fruits
- Vegetables
- Whole grains
- Seeds, nuts, or legumes (such as peanuts or lentils)
- Lean protein
Cook with healthy oils, such as olive oil. And try to limit processed foods such as candy and chips, which are often high in sugar and fats but low in nutrients.
Foods to avoid with hyperthyroidism
Eating foods that are high in iodine can make hyperthyroidism worse. You'll probably need to stay away from foods such as:
- Iodized salt
- Dairy products
- Egg yolks
- Cheese
- Sushi
- Seaweed
- Lobster
- Crabs
- Prawns
Talking to a dietitian can help you understand the foods you need to avoid, and what you can eat instead.
Takeaways
If you have symptoms of an overactive thyroid, talk to your doctor. Several treatments can help lower your thyroid hormone levels so your symptoms improve. If left untreated, hyperthyroidism can cause other severe health issues.
Hyperthyroidism FAQs
How to stop weight gain with hyperthyroidism?
Once you start treatment for hyperthyroidism, it's common to gain some weight. You're probably putting on the pounds you lost when you had too much thyroid hormone and your body needed more calories to function. Or you could have gotten used to having a bigger appetite and eating more.
If you're worried about your weight, talk to your doctor or a nutritionist. They can give you ideas for healthy meals.