Chapter
10

Hyperthyroidism Symptoms

In This Chapter

• Signs that you’re hyperthyroid
• Causes and effects of Graves’ disease
• Plummer’s disease’s rogue nodules
• Becoming hyperthyroid from iodine

If your heart is racing, you’re feeling anxious, you’re losing weight for no apparent reason, or you’re experiencing any of dozens of other symptoms, you may be hyperthyroid.

Over 90,000 Americans every year are diagnosed with hyperthyroidism, and millions of people suffer from it worldwide. It strikes over five times as many women as men, and the odds of becoming hyperthyroid increase with age.

In addition to those genetically disposed to the disease, hyperthyroidism is an ever-present danger for the tens of millions of people being treated for hypothyroidism. That’s because your body reacts the same whether you have an overactive thyroid or consume too much thyroid medication.

This is the first of three chapters providing you with the knowledge you need to meet the various challenges posed by hyperthyroidism. Once you’ve read these chapters, you’ll know whether you should see a doctor; and how to make sure you receive the best testing, diagnosis, and treatment.

Hyperthyroidism Symptoms Checklist

As explained in Chapter 1, your thyroid regulates the energy level of every cell in your body through the production of its hormones. Hyperthyroidism occurs when the levels of those hormones are above normal. In fact, the first part of this disease’s name, hyper, is Greek for over (just as hyperactive refers to being overly active).

The excess hormones increase the activity of cells throughout your body, which can be so overstimulating that you may feel as if you’re perpetually drinking a big pot of black coffee.

Because thyroid hormones affect every cell, in theory an overactive thyroid can result in any of hundreds of symptoms. In general, though, certain symptoms are more likely to occur than others. These frequent clues to hyperthyroidism appear in the checklist that follows.

Take a few minutes to go over the list and check off any symptom that applies to you. If you aren’t sure whether you have a particular symptom, find the description of it in Chapter 2 and use the additional information to make your decision.

Hyperthyroidism Symptoms Checklist

• ❑ Severe anxiety and panic attacks
• ❑ Irritability
• ❑ Shakiness, including hand tremors
• ❑ Heart pounding in chest at over 90 beats per minute while at rest
• ❑ A racing mind that makes it difficult to focus
• ❑ Insomnia
• ❑ Losing weight for no apparent reason (or gaining weight due to an abrupt increase in appetite)
• ❑ Feeling overheated
• ❑ Oversweating (especially in the head, hands, and feet)
• ❑ Tingling in the hands and feet
• ❑ Frequent bowel movements and/or a loose stool
• ❑ Menstrual problems
• ❑ A sex drive that’s in overdrive
• ❑ Weak muscles
• ❑ Thinning hair
• ❑ Thyroid growths, called goiters
• ❑ Eyes sensitive to light
• ❑ A dry, gritty feeling in the eyes
• ❑ Enlarged, protruding eyes (creating a “bug-eyed” look)

If you have six or more of these common symptoms, there’s a strong chance you’re hyperthyroid. Get your thyroid checked out—typically via blood tests for TSH, free T4, free T3, and thyroid antibodies—as soon as possible.

If you have two to five of these symptoms, that’s still reason enough to get your thyroid tested. Either the results will be positive, putting you on the path to treatment; or negative, which will inform your doctor to explore other potential problem sources.

But even if you have only one of these symptoms and your doctor isn’t providing a satisfying explanation for its cause, you should seriously consider getting tested. That’s especially true if you’re a woman, as you’re at over five times greater risk than a man of being struck by hyperthyroidism.

The checklist is by no means comprehensive; you can definitely experience other symptoms. However, the odds are that along with the unlisted symptoms you’ll have at least a few of the ones on the checklist—and the latter are all the clues you need to go get tested.

If you’re successfully treated, you’ll soon experience improvement regarding all your hyperthyroidism symptoms.

Thyroidian Tip

Some of the symptoms on the checklist apply to both hyperthyroidism and hypothyroidism—for example, insomnia, weak muscles, thinning hair, goiters, menstrual problems, and gaining weight. In each case, the problem stems from different causes but has the same result. Fortunately, all you need to do is see a doctor who’ll test your blood for thyroid disease. The lab results will reveal your condition.

Hyperthyroidism Dangers

Some people actually enjoy being hyperthyroid at first. During its initial, milder stages you can become unusually productive, especially at low-level tasks like cleaning out the garage. But at a certain point hyperthyroidism may become not only unpleasant, but horrific.

For example, one of my patients was a photojournalist who risked his life covering wars and taking pictures of soldiers during combat. He told me the anxiety he experienced was so gut-wrenching that he’d felt safer and more comfortable being shot at on battlefields than he did sitting at home with his family during hyperthyroid-induced panic attacks.

As another example, early on in my career I took thyroid medication I didn’t need to understand what my hyperthyroid patients were going through. It was one of the worst experiences of my life. Perhaps it made me a better doctor, but I wouldn’t recommend anyone to willingly go through such an ordeal.

In addition to the overt symptoms, hyperthyroidism can cause bone loss (osteoporosis), cardiovascular damage that can lead to a heart attack, and pressure on ocular nerves that can eventually lead to blindness.

In fact, one of the few advantages of hyperthyroidism is that it’s not subtle. Especially in its later stages, its symptoms are so severe that most doctors are able to quickly spot them and identify their cause.

Otherwise, as awful as hypothyroidism is, hyperthyroidism is worse. In fact, among the prime cures for hyperthyroidism is turning you hypothyroid instead—typically via drugs, surgery, or radiation that reduces your thyroid’s functionality. At that point your condition can be managed via hypothyroid medication.

Throat Quote

It is those who have enough but not too much who are the happiest.

—Peace Pilgrim

Graves’ Disease

Roughly 80 percent of hyperthyroidism results from Graves’ disease. This grim-sounding illness doesn’t derive its name from its outcome—it’s actually highly treatable—but from an Irish doctor named Robert James Graves who was the first to write about it in detail in 1835.

Graves’ disease strikes women about seven times as often as men. It most commonly occurs during early adolescence and ages 20-40, but can happen at any age. Graves’ is an autoimmune disease. It occurs when your immune system—which normally protects you by attacking foreign invaders such as bacteria and viruses—mistakes your thyroid as a danger and starts attacking it, too.

Graves’ is typically caused by a genetic disposition for an autoimmune problem—it runs in families—coupled with a trigger that pushes the immune system over the edge.

That said, most of the triggers for Graves’ disease are unknown. The only proven culprit to date is an excess of iodine, the key chemical your thyroid uses to make its hormones. Your thyroid is designed to sift through your blood, and suck in and store even the tiniest amounts of iodine it finds. This ability is normally wonderful, because it means you need to consume only a little bit of iodine daily to have enough T3 and T4. If you have a genetic disposition for Graves’, however, your thyroid’s sensitivity to iodine may cause your body to identify even a mild overdose as toxic … and as a reason to mobilize your immune system.

Then again, something else can set your immune system on alert—for example, accidentally consuming mercury, which really is poisonous, and is so similar to iodine in chemical composition that it’ll be absorbed by your thyroid.

Whatever the trigger, your immune system will respond by creating antibodies to flush it from your system. Unfortunately, what often happens if you’re predisposed to Graves’ is the antibodies will mistake your thyroid cells as being a threat along with whatever triggering chemical they’re storing. The antibodies will respond by attacking your entire thyroid; and there’s no practical way to stop them. (Your doctor could shut down your immune system, but that would be a “cure” leaving you vulnerable to hundreds of other illnesses.)

As with Hashimoto’s disease (see Chapter 5), this may involve thyroid peroxidase antibodies and thyroglobulin antibodies. But the primary cause of Graves’ is thyroid stimulating immunoglobulin antibodies, or TSI. TSI is unique because at the same time that it’s attacking your thyroid’s cells, it’s stimulating them into producing more hormones.

TSI has essentially the same effect as the thyroid stimulating hormone, or TSH, secreted by your pituitary gland (see Chapter 1). However, while TSH production is linked to the amount of T3 and T4 in your bloodstream and is designed to maintain balanced thyroid hormone levels, TSI is produced with no regard to your body’s thyroid levels, and with no limits. In other words, TSI is like a rogue, insane version of your pituitary gland; and it makes your thyroid produce much more T3 and T4 than your body needs.

The results include all the symptoms of hyperthyroidism previously described—elevated heart rate, panic attacks, tremors, etc. In addition, the extra activity frequently leads to one or more goiters, which are enlargements of your thyroid, and to eye problems. If left untreated, Graves’ will become progressively more severe. Fortunately, there are a variety of treatment options for this disease (described in Chapter 12).

Thyroid Factoid

Graves’ disease has a lot in common with Hashimoto’s disease—they’re both autoimmune thyroid conditions, and they’re both responsible for the vast majority of thyroid disease. The key difference is that the antibodies that cause Hashimoto’s attack the inner proteins of the thyroid, which breaks down its cells. In contrast, Graves’ is caused by TSI antibodies that attack the thyroid’s receptors for TSH—and in the process continually stimulate them. Even after your pituitary gland shuts down in response to your body having too much T3 and T4, the stimulation from the TSI ensures your thyroid will continue to overproduce hormones and keep you hyperthyroid.

Goitrous Hyperthyroidism

A goiter is a non-cancerous swelling on your thyroid. Your thyroid can grow one goiter or multiple goiters. This condition isn’t really a disease, but a side effect of diseases such as Graves’.

If you’re hyperthyroid, you’ll typically develop goiters when TSI antibodies relentlessly stimulate your thyroid to overproduce. Because your thyroid isn’t capable of making enough hormones to meet the antibodies’ demands at its current size, it grows more cells. This is an effective response when you’re healthy, as producing additional T3 and T4 until your bloodstream has a sufficient supply will end your body’s requests for these hormones. However, no amount of overproduction will satisfy the limitless demands of the TSI antibodies, which means TSI will make your thyroid keep growing and growing.

If your hyperthyroidism is successfully treated in its early stages with medication, any existing goiters will stop getting bigger, and may even fade away over time. That’s because once the TSI stimulation ends, your thyroid will stop replacing dying goiter cells with fresh ones, resulting in natural shrinkage. Alternatively, if your treatment involves surgery or radiation, any goiters can be removed or destroyed as part of the procedure.

Hyperthyroid Eye Disease

If you’re hyperthyroid, you’re almost certain to have “lid lag.” Your doctor can spot this by having you follow her finger as she moves it up and down. If the white part of your eye can be seen above your iris as you look down, it’s a strong indication you’re hyperthyroid.

If you have Graves’ disease, there’s also a roughly 30 percent chance that you’ll develop more severe eye problems. For example, you can become sensitive to light. You may feel a painful dryness or grittiness in your eyes. Or you may experience double vision (called diplopia).

As the disease progresses, your eyelids may retract, and your eyes enlarge and protrude, creating a “bug-eyed” look. If left untreated, this is a serious condition that can put pressure on your optic nerves and eventually lead to blindness. If treatment occurs soon enough, distended eyeballs will return to normal on their own after the disease is under control. Past a certain point of growth, though, surgery may be required.

Crash Glanding

If your Graves’ eye disease has been brought under control, keep a sharp lookout for any signs of its return. Graves’ eye disease can come back, and grow worse, even when all your other hyperthyroidism symptoms are being well managed.

Plummer’s Disease

Plummer’s disease is the second most common cause of hyperthyroidism. It occurs most often in women, and after age 50. Named after acclaimed American endocrinologist Henry Stanley Plummer (who co-founded the Mayo Clinic), Plummer’s disease is caused by one or more non-cancerous thyroid growths, or nodules, that produce hormones independently—that is, without waiting to be stimulated by TSH. These nodules are referred to as “toxic” because they churn out hormones at such high levels that they’ll make you hyperthyroid.

A single toxic nodule is called Plummer’s adenoma (adenoma is another name for a non-cancerous growth). Plummer’s disease can also take the form of a toxic multinodular goiter, in which a number of such nodules spring up on a goiter.

Plummer’s disease is typically triggered by insufficient iodine. Specifically, because iodine is the chemical your thyroid needs to make its hormones, a lack of it will lead to low levels of T3 and T4. The thyroid responds by growing more cells in a dysfunctional attempt to make additional hormones—which over time leads to goiters. The goiters then develop smaller growths, called nodules; and these nodules can mutate to produce hormones independently. Once enough iodine is available to make T3 and T4 again, these toxic nodules will turn you hyperthyroid.

Alternatively, though, Plummer’s disease can be triggered by an abrupt large amount of iodine. This is covered in the next section.

Iodine-Induced Hyperthyroidism

Taking in an excessive amount of iodine can put you at risk of becoming hyperthyroid. This most commonly happens if you already have thyroid nodules. The iodine overload can transform existing harmless nodules into a “toxic” state in which they produce hormones independently. If the excess iodine is withdrawn, this can be a temporary condition. If you’re over 50, though, just one incident can be the trigger for a permanent condition such as Plummer’s disease.

For example, a 62-year-old patient named Ricardo came to see me when he was having increasingly frequent bowel movements and very loose stools for no apparent reason. When I checked his pulse, Ricardo’s resting heart rate was 100.

Considering Ricardo’s age and hyperthyroid symptoms, I asked him if he’d recently had any imaging tests for which he’d been given an injection. He told me that he’d had a CT scan a few months ago that used iodine to help create a clear contrast.

I took Ricardo’s blood and ordered hyperthyroidism testing, and also prescribed an ultrasound for his neck. I wasn’t surprised when the lab results showed low TSH and high T4 levels. Thyroid antibodies were negative, ruling out Graves’ disease. And a single nodule actively producing hormones was visible via the ultrasound, which confirmed my suspicion of Plummer’s disease.

Within the first month of treatment, Ricardo’s heart rate settled, and his bowel movements returned to normal.

Painful Subacute Thyroiditis

If your thyroid feels inflamed, you may have painful subacute thyroiditis. This typically occurs following a respiratory infection—for example, after you’ve had the mumps, or the flu, or some other virus. If your body’s attacks on the virus create high inflammation, that can in turn spawn antibodies that end up attacking your thyroid.

As your thyroid cells are destroyed, the hormones they stored are abruptly released into your bloodstream, making you hyperthyroid. This condition tends to be temporary. However, you should be treated for its symptoms until it goes away on its own.

More information about this disease—as well as other forms of thyroiditis that include stages of hyperthyroidism—appears in Chapter 15.

However, this is a temporary state. As the Hashimoto’s continues its assault over months, your thyroid will eventually become so damaged that it lapses into a permanent stage of hypothyroidism.

Thyrotoxicosis Factitia

Thyrotoxicosis factitia is a condition in which hyperthyroidism occurs as a result of artificial rather than natural causes. The most typical cause is an overdose of thyroid medication. Taking in too much T4 and/or T3 via pills has the same effect on your body as an overactive thyroid that makes too much of its hormones.

A patient can intentionally overdose in a misguided attempt to lose weight, or to overwhelmingly combat some other hypothyroid symptom. It’s also possible to overdose by simply staying on your thyroid medication without sufficiently frequent testing. Sometimes your thyroid will grow healthier with treatment and begin producing higher levels of hormones, which is a good thing; but unless your doctor detects this and decreases your dosage accordingly, you’ll end up taking more medication than you need.

Thyroid Factoid

In rare cases, it’s possible to consume excess thyroid hormones from meat. There have been at least two outbreaks in which the thyroid tissue in neck muscles were accidentally ground up along with other cow parts for burger patties. These resulted in “hamburger hyperthyroidism” for entire communities.

The simple solution to these situations is to stop taking the excess hormones. The hyperthyroidism symptoms will then usually go away on their own. If the overdosing goes on for months, though, there’s a risk of triggering permanent hyperthyroidism.

TSH-Secreting Pituitary Adenoma

Less than 1 percent of hyperthyroidism cases are caused by a condition called TSH-secreting pituitary adenoma. As explained in Chapter 1, your thyroid’s activities are regulated by your pituitary gland. When your body is running low on energy, your pituitary secretes TSH to tell your thyroid to get to work and make more hormones.

This is a great system when everything is working normally. However, just as your thyroid can grow a toxic nodule, the pituitary gland can develop a non-cancerous growth (an adenoma) that turns rogue and independently produces TSH. In contrast to your pituitary’s generating TSH based on your body’s needs, the adenoma arbitrarily makes excessive amounts of TSH.

All TSH looks alike to your thyroid, so it’ll obey the orders of the adenoma just as fully as the ones from your pituitary gland. Even though your thyroid is healthy, you’ll end up with way too much T3 and T4, and become hyperthyroid.

You may also experience other things going wrong. For example, in addition to thy-roid hormones, your pituitary gland is responsible for regulating the production of prolactin. Therefore—even if you’re a man—you may abruptly start lactating, which normally occurs only in women after childbirth.

The presence of a pituitary adenoma can be picked up by blood tests that show both high TSH and high levels of thyroid hormones. Since TSH and T4/T3 normally have an inverse relationship—when one is high, the other is low, and vice versa—all levels being high indicates an out-of-control pituitary gland whose TSH production is no longer fully connected to your body’s needs. The condition can then be confirmed by an MRI of your pituitary gland, which will show an active adenoma growing on it.

If the adenoma is small—under 14 millimeters—it can often be shrunk down until it’s harmless via such medications as bromocriptine and cabergoline.

Otherwise, you’ll require surgery on your pituitary gland to remove the adenoma. This is especially important because in addition to making you hyperthyroid, continued growth of the adenoma threatens to put pressure on and damage your nearby optic nerves.

Struma Ovarii

In very rare cases—well under 1 percent—a woman may develop an ovarian tumor with thyroid tissue, called struma. Thyroid cells don’t belong in the ovaries, but sometimes cells grow in inappropriate places. If the struma is distinct enough to not respond to TSH, but similar enough to your thyroid to produce hormones, the excess T3 and T4 will make you hyperthyroid. This condition is treated by surgical removal of the struma.

The Least You Need to Know

• Hyperthyroidism symptoms include anxiety, panic attacks, rapid heartbeat, tremors, weight loss, insomnia, diarrhea, and sensitivity to light.
• Severe dangers of untreated hyperthyroidism include osteoporosis, heart attack, and blindness.
• The most common cause of hyperthyroidism is an autoimmune disorder called Graves’ disease, which causes goiters and eye problems.
• The second most common cause of hyperthyroidism is Plummer’s disease, which creates nodules that independently produce thyroid hormones.
• Other causes of hyperthyroidism include an autoimmune response to infection, too much thyroid medication, and an overactive pituitary gland.