hyperthyroid symptoms
Toxic diffuse goiter, Flajani-Basedow-Graves' disease. 3D illustration showing enlarged thryoid gland in a female with hyperthyroidism

The thyroid gland is a tiny, butterfly-shaped organ at the bottom of your neck. This small gland has a significant effect on your body. The hormones it produces affect almost all bodily processes, including metabolism, fertility and sexual function, an internal thermostat, mood, and more.

The American Thyroid Association concludes that more than 12% of Americans will develop a thyroid condition at some point in their life. However, up to 60% of those with thyroid disease are unaware of their condition. Women are more likely than men to have thyroid problems, with around one in every eight women developing a problem at some point in her life.

Hyperthyroidism, in which too much thyroid hormone circulates in the body, is a common thyroid condition, affecting more than one in every hundred Americans. While there are many effective hyperthyroidism treatments, uncontrolled hyperthyroidism can lead to serious, even life-threatening problems. Read on to learn more about hyperthyroidism, the symptoms, and how to live with this condition.

How the Thyroid Works

The thyroid gland is part of your endocrine system. The endocrine system is the network of glands throughout your body that produces hormones – powerful chemicals that help turn on or off all of the body’s various functions. The thyroid is an essential element of the endocrine system, producing hormones that affect the brain, heart, kidney function, skin maintenance, digestion, fertility, temperature regulation, muscle strength, and more.

To produce thyroid hormones, the thyroid uses iodine from our food to create two hormones: triiodothyronine (T3) and thyroxine (T4), which affect the function of all the cells in the body. The thyroid also produces a more targeted hormone, calcitonin, which helps regulate the amount of calcium in your blood.

The pituitary gland, located in the brain, tells the thyroid how much hormone to produce by releasing thyroid-stimulating hormones (TSH). When everything is functioning as it should, the hypothalamus and the pituitary gland carefully monitor hormone levels in the body. The pituitary releases TSH to stimulate the thyroid to produce just the right amount of thyroid hormone. These hormones circulate in the blood and are taken up by various organs to help run just about every system in the body.

Symptoms of Hyperthyroidism

While the thyroid gland usually keeps our metabolism and other functions humming along correctly, sometimes it goes haywire. When the thyroid produces too little hormone, it causes hypothyroidism, in which everything in the body slows down. People with hypothyroidism gain weight, feel cold, fight fatigue and depression, and more.

In contrast, with hyperthyroidism, too much thyroid hormone is present in the body, causing bodily functions to speed up. Symptoms include:

Weight loss, despite increased appetite
Lighter or missed periods
Rapid heartbeat (tachycardia), irregular heartbeat (arrhythmia), or a pounding heart (palpitations)
Anxiety, irritability, and nervousness
Uncontrolled sweating and heat intolerance
Difficulty sleeping
Thin, brittle hair
Red, swollen skin on the shins and feet

In some cases, people with hyperthyroidism caused by an autoimmune condition known as Graves’ disease will develop an eye condition known as Graves’ ophthalmopathy. In this condition, the same autoimmune antibodies that cause the thyroid to overproduce thyroid hormone also cause inflammation in the tissues behind the eye. This can cause bulging eyes, dry eyes, watery eyes, and eye pain and inflammation.

Graves’ ophthalmopathy usually develops soon after hyperthyroid symptoms, but it can develop years later. In some people, eye irritation will be the first sign of a thyroid problem. Many cases of Graves’ ophthalmopathy will resolve on their own, but all claims should be monitored by an eye doctor, as it can cause vision loss in extreme cases.

If hyperthyroidism goes untreated, several complications can result, including:

Heart problems: Hyperthyroidism increases the heart rate. Over time, this stresses the heart, increasing the risk of heart disease, stroke, and congestive heart failure.

Brittle bones: When your body has high thyroid hormone levels, your bones can’t properly absorb calcium, leading to osteoporosis.

Thyroid storm (thyrotoxic crisis) – In rare cases, the body produces far too much thyroid hormone, leading to a potentially life-threatening condition marked by rapid heart rate, sweating, high fever, and confusion. Thyroid storm requires immediate medical treatment.

Who Gets Hyperthyroidism?

Hyperthyroidism can develop in anyone at any age, but it occurs most often in women, and the risk rises after age 60. In older people, hyperthyroidism symptoms can be subtle, and doctors sometimes mistake it for depression or dementia. If someone has uncontrolled hyperthyroidism and gets pregnant, hyperthyroidism can sometimes affect the baby.

Risk factors for hyperthyroidism include:

A family history of thyroid problems, particularly Graves’ disease
Health problems including pernicious anemia (a vitamin B12 deficiency), type 1 diabetes, and primary adrenal insufficiency, a disorder that affects the hormones
Being female
Being older than age 60
Consuming large amounts of iodine from medications or food
Recent pregnancy
Extreme stress or trauma, which can trigger Graves’ disease in people with a genetic susceptibility

While some people may be more at risk of hyperthyroidism than others, anyone can get it. Hyperthyroidism has several causes, including:

Graves’ disease, mentioned above – an autoimmune disorder in which the immune system attacks the thyroid, causing it to overproduce T4. Graves’ disease is the most common cause of hyperthyroidism.

Hyperfunctioning thyroid nodules occur when a small piece of the thyroid malfunctions, creating small, benign (non-cancerous) nodules or lumps. These nodules pump out thyroid hormones and do not respond to TSH levels.

Thyroiditis, or inflammation of the thyroid, can occur after pregnancy. An infection or virus can also cause thyroiditis. In thyroiditis, the inflamed thyroid begins to leak stored thyroid hormone into the bloodstream.

Excess iodine consumption. The thyroid makes thyroid hormones out of iodine. If someone consumes too much iodine, it may spur the production of excess thyroid hormone. Iodine is present in some medications, including some heart medications and cough syrups. Seaweed and seaweed supplements also contain iodine, as does table salt with added iodine.

Excess thyroid medication. People who take medicine for hypothyroidism (low thyroid hormone levels) can experience hyperthyroid symptoms if their dose of medication is too high. It’s essential that if you are taking medication for hypothyroidism that you have your thyroid levels checked from time to time, as your levels – and the dose of medicine you require – can change over time.