Hyperthyroidism

Symptoms: Weight loss despite an increased appetite, rapid or irregular heartbeat, nervousness, irritability, trouble sleeping, fatigue, shaky hands, muscle weakness, sweating or trouble tolerating heat, frequent bowel movements, an enlargement in the neck, called a goitre, etc.

Causes: The most common causes include grave disease, thyroid nodules and thyroid gland inflammation.

Risk factors: Age, gender, pregnancy, Iodine exposure, family history, underlying conditions and smoking, etc.

Prevalence: In iodine-deficient areas, the prevalence of hyperthyroidism is higher: up to 10-15% for both overt and subclinical hyperthyroidism combined, with toxic nodular goitre being more common than Graves disease.

Severity: Mild to severe

Which doctor to consult: Endocrinologist

Overview: 

Hyperthyroidism is defined as a medical condition in which your thyroid gland releases/produces high levels of thyroid hormones. This condition is also known as an overactive thyroid. A thyroid gland is a small, butterfly-shaped gland located in the front of your neck. 
The main function of this gland is to regulate the body’s metabolism, a process of converting food into energy. This medical condition can affect the individual's metabolism and lead to symptoms such as weight loss, increased appetite, etc. 
The thyroid gland produces two hormones, namely T3 (triiodothyronine) and T4 (thyroxine). These hormones are mainly responsible for controlling the use of energy by the cells in the body. If left untreated, it can cause serious problems to your heart, muscles, menstrual cycle, fertility and bones.

Types:

Hyperthyroidism is of different types:

1. Primary hyperthyroidism: This is, also known as thyrotoxicosis, is a condition in which the disease lies within the thyroid gland. This leads to excess production of thyroxine. Primary hyperthyroidism occurs due to various conditions, such as:
•    Graves' disease is an autoimmune condition that causes excess thyroid-stimulating immunoglobulin (TSI) production. This TSI begins targeting the thyroid gland, which stimulates the thyroid to make excessive thyroid hormone. Most cases of this illness run in families, and this condition is more likely to affect women.

•    Thyroid nodules: A thyroid nodule is a lump or group of cells that produce more than the required hormone, causing an overactive thyroid. This overactive thyroid nodule is usually large (an inch or more in size) and non-cancerous.

•    Iodine: Iodine is a mineral the thyroid gland uses to produce thyroid hormones. Too much iodine, through diet supplements and medications, can result in high thyroid hormone levels.

2. Secondary hyperthyroidism: It is a rare condition that arises due to over-stimulation of the thyroid gland. This can be caused by the overproduction of TSH from non-cancerous pituitary tumours. This condition can also rarely, occur due to the overproduction of TRH. The hypothalamus produces thyroid-releasing hormone (TRH) that stimulates TSH and thereby increases the levels of TSH. Symptoms include bone deformities, bone pain, fractures, joint pain, kidney stones, and irregular heartbeat.

3. Subclinical hyperthyroidism: This condition causes low or undetectable levels of TSH with a normal level of thyroid hormones. It can be caused by medical disorders such as Graves' disease, multinodular toxic goitre (enlarged thyroid gland), and thyroiditis. Medications such as glucocorticoids, amiodarone, and dopaminergic drugs can also cause subclinical hyperthyroidism. Symptoms may include frequent bowel movements, fatigue, tiredness, increased appetite, and increased sweating.

4. Hyperthyroidism in neonates: This condition rarely occurs in neonates of moms with Graves' illness. In rare instances, moms who have previously received treatment for Graves disease may experience hyperthyroidism in their newborns, which would suggest a remission of the illness. Sometimes, it is also seen in newborn babies of mothers with a normal thyroid gland function (euthyroid). Symptoms include tachycardia, hyperexcitability, poor weight gain, irritability, and prominent eyes.

Symptoms:

Hyperthyroidism may cause many symptoms. Every individual with hyperthyroidism may not experience all these symptoms. It can vary from person to person and the type of condition.

• Palpitations

• Rapid heartbeat

• Irregular heartbeat

• Unexplained weight loss

• Increased appetite

• Nervousness

• Irritability

• Trembling in your hands and fingers 

• Increased frequency of bowel movements

• Diarrhoea 

• Double vision

• Menstrual changes 

• Sleep disorders

• Intolerance towards heat 

• Excessive sweating 

• Enlarged thyroid gland

• Brittle hair 

• Bulging of the eyes

• Muscle weakness

• Bone pain

• Joint pain

• Fatigue

• Trouble sleeping

• Mood swings

Causes:

Hyperthyroidism can occur due to various underlying conditions. The most common causes include grave disease, thyroid nodules and inflammation of the thyroid gland. The TSH (thyroid stimulating hormone) is a pituitary hormone that stimulates the thyroid gland to produce thyroid hormones (T3, T4). These hormones affect almost every organ in your body. It helps maintain the body’s metabolism, body temperature, heartbeat, and breathing.

This condition can also occur due to excessive iodine production, excessive thyroid medicine intake, or the presence of a non-cancerous tumour in the pituitary gland. Usually, hyperthyroidism occurs when the body produces an excess of TSH or the thyroid gland releases too much thyroxine (T4).

Risk Factors:

The main risk factors of hyperthyroidism include:

Age: If you are older, especially above 60 years of age, then you can be at higher risk for hypothyroidism.
Gender: Both males and females are affected by hyperthyroidism; however, most females are at greater risk for this condition.
Pregnancy: Some people may become hyperthyroidism during pregnancy or were pregnant within the past 6 months, which can lead to difficulties for both the mother and the fetus.
Iodine exposure: Patients with intake of too much iodine can lead to hyperthyroidism.
Family history: If any of your family members have a history of this condition, then you are at the greatest risk for hyperthyroidism.
Underlying conditions: People with type 1 diabetes, primary adrenal insufficiency, or pernicious anaemia (Vitamin B12 deficiency) are considered more at risk.
Smoking: Avoid smoking, as it can also be one of the risk factors for hyperthyroidism.
This medicine can also occur in patients with overtreated hypothyroidism.
Food: Individuals eating large amounts of food containing iodine are at higher risk.

Complications:

If you do not consult the doctor and leave the condition untreated, it can affect different body parts and cause complications such as:

Cardiac problem: One of the main side effects of hyperthyroidism includes fast or irregular heartbeat. It occurs due to the fast metabolism, causing the body to function faster than usual. This results in medical conditions like stroke and congestive heart failure.

Pregnancy: It is always important to inform your doctor of your diet plan and whether you are pregnant or not. Mostly, women with a history of Graves’ disease, which is untreated, may have complications like irregular menstrual cycle and difficulty conceiving.

Infertility: Hyperthyroidism can significantly decline men's sperm counts, which has an impact on their fertility. When the thyroid condition is corrected, the count returns to normal.

Brittle bones: Uncontrolled thyroid hormone levels might damage your bones and weaken your skeletal system. This condition can cause osteoporosis. The amount of calcium and other minerals in bones somewhat affects their strength. This causes difficulty in absorbing calcium into bones due to high thyroxine levels.

Vision and skin problem: Graves' disease-related hyperthyroidism impacts the skin and eyes (thyroid eye disease). This disease is mostly seen in patients who smoke. Muscles and other tissues of the eye are mostly affected. Symptoms may include puffy eyes, vision loss, redness, swelling, double vision, and sensitivity to light.

Thyroid storm: Also known as thyrotoxic crisis, is a potentially fatal illness and serious complication of hypothyroidism. It happens when thyroid hormone levels suddenly and severely rise. Symptoms include increased body temperature and an abrupt shift in mental state, such as disorientation or drowsiness, blood pressure, nausea, vomiting, confusion, and heart rate.

Prevention:

Most of the time, hyperthyroidism cannot be prevented. Individuals who are more likely to develop hyperthyroidism might choose to live a healthy lifestyle by giving up smoking, eating a balanced diet, and exercising frequently. Consult your doctor regarding routine checkups if you have a family history of Graves’ disease, as it can be one of the major causes of hyperthyroidism.

When to see a doctor?

You should visit an endocrinologist or a general healthcare professional if you have symptoms such as heat intolerance, weight loss, increased appetite, brittle hair, excessive sweating, tremors, or rapid heartbeat. Your doctor will advise a diagnosis based on your physical examination and signs and symptoms.

Diagnosis:

The hyperthyroidism condition has certain tests that can prove the disease before starting further treatment. This includes:

Physical examination
A physical examination will be done to check for the feeling of the size of the thyroid gland. Your doctor will also examine the skin, eyes, and heart.

Blood tests: Your doctor will suggest a blood test to check your thyroid hormone levels before confirming the disease. This test includes the following:

a)    Triiodothyronine (T3): Hyperthyroidism patients usually have high T3 levels. The amount of protein that binds to them will determine whether the hormone is bound or free in circulation. Total or free T3 can be used to quantify the T3 hormone. The triiodothyronine (T3) total test, typically performed as a component of the thyroid profile total test, quantifies the total amounts of the hormone (free and bound forms) in the blood.

b)    Thyroxine total (T4): An elevated T4 blood level could indicate hyperthyroidism. Bound T4 and free T4 are included in the T4. The entire amount of thyroxine bound to a protein is known as bound T4, whereas the free amount is known as free T4. Thyroxine-binding globulin is a protein that binds most of the T4 in the blood. Most of the time, bound T4 cannot enter bodily cells, and only about 1%–2% of free T4 in the blood can enter cells. Simple blood tests that measure the amount of unattached T4 in the blood that is available to enter cells are the free T4 and the free T4 index.

c)    Thyroid stimulating hormone (TSH): This is the most significant and accurate test for hypothyroidism. It calculates the amount of thyroxine (T4) that the thyroid gland is required to produce. A low TSH level indicates an overactive thyroid. This implies that the hormone produced in excess by the thyroid gland is what is causing the pituitary to cease secreting TSH into the bloodstream. Your doctor may suggest an extra test to confirm the diagnosis if the TSH levels are abnormal. 

Along with the thyroid profile, further tests may be required to evaluate and monitor the condition based on the disease, such as:

Anti-thyroglobulin antibody

Thyroxine binding globulin

Imaging tests:
If your doctor finds any change in your thyroid profile, he may suggest a few more tests. Which include imaging tests that can be used to find the cause of hyperthyroidism.

1) Thyroid scan: This can help more accurately evaluate the thyroid gland's size, shape, and position. This test uses a small amount of radioactive iodine to help diagnose the cause of hyperthyroidism and check for thyroid nodules as well.

2) Radioactive iodine uptake test: The thyroid uptake test is another name for the radioactive iodine uptake test. It quantifies the quantity of radioactive iodine that the thyroid gland absorbs from the blood after swallowing a small amount of it. It can assist in determining the aetiology of hyperthyroidism and monitoring thyroid function.

3) Ultrasound: The thyroid is also examined using ultrasound. Thyroid nodules are solid or fluid-filled lumps or masses of cells that form within the thyroid gland. Ultrasound can help the doctor determine whether the nodules are cancerous.

Treatment:

To address hyperthyroidism, there are multiple treatment modules. Depending on the patient's age, general health, underlying cause, and degree of the disease, your doctor will decide the optimal course of action. The treatments include:

Lifestyle and home remedies:
Generally, patients diagnosed with hyperthyroidism can face certain changes in the body. Hence, changing their lifestyle to avoid further complications will be beneficial. These include:

• This condition causes anxiety and stress as a side effect. Additional stress can worsen your disease condition. Hence, doing yoga regularly and meditation can help reduce these symptoms.

• Hyperthyroid patients may lose weight. Elevated thyroid function speeds up the body's metabolism, leading to unintentional weight reduction, which can cause further complications. Hence, consult your doctor to learn about healthy weight management.

• Maintaining a healthy and good food diet is one of the key factors in hyperthyroidism patients, especially in Graves’ illness patients. This disease causes sudden weight loss and increased appetite as a side effect. Therefore, try to eat healthy food in small amounts at different intervals. Mostly, avoid the intake of sugary products as they can fasten insulin metabolism, resulting in insulin resistance in diabetic patients.

• Also, avoid smoking. Patients with Graves’ disease can develop vision problems. This can worsen due to smoke. Hence, avoid smoking if you are diagnosed with hyperthyroidism.

Antithyroid medications:
The thyroid gland produces less thyroxine hormone with anti-thyroid medication. Although it is the easiest treatment course of action, this remedy frequently does not last long. On average, a patient taking this medicine should anticipate a one- to two-year therapy period. The medications may need to be used for several years in certain situations. Patients with Graves' illness may see a temporary improvement in their symptoms after using these drugs. These medications are not used for the treatment of hyperthyroidism caused by thyroiditis.

The anti-thyroid drugs that the physician most often recommends include methimazole and propylthiouracil. These cause certain side effects such as allergic reactions, reduction in the body's white blood cells, nausea, skin reactions, vomiting, stomach upset, etc. Pregnant and breastfeeding mothers should inform the doctor as this is known to cause harm to the baby.

Beta-blockers:
These drugs block the effect of thyroid hormones on the body. It generally acts by widening or relaxing the blood vessels. These drugs are not used alone but as an adjunct to another treatment option in hyperthyroidism patients over the long term.

Beta-blockers and other treatment options help reduce symptoms like irritability, tiredness, tremors, rapid heartbeat, and nervousness until other treatments start working.

Radioactive iodine therapy:
It is a popular and successful way to manage hyperthyroidism. The patient is instructed to ingest liquid or capsules containing radioactive iodine-131. It targets only the thyroid gland and gradually kills the cells that make thyroid hormones in the gland. However, because radioiodine therapy permanently destroys the thyroid, patients eventually develop hypothyroidism. It can be managed by taking daily thyroid hormone medications to maintain normal hormone levels. Occasionally, a person can lose sensation in their mouth after the therapy. The sensation loss may last for up to a year but returns to normal later. Pregnant or breastfeeding mothers shouldn't take radioactive iodine as it can affect the baby's thyroid glands.

Thyroid surgery:
Thyroidectomy, or surgery to remove the excess thyroid gland, has been less prevalent with the development of antithyroid medications and radioactive iodine therapy. In this procedure, the thyroid gland is removed whole or in part. Physicians mostly prescribe this procedure for Patients with very big thyroid glands experiencing dysphagia, hoarseness, and dyspnea and in children and pregnant women who may experience adverse effects from antithyroid drugs.
Following surgery to remove a portion of the thyroid gland, hypothyroidism may result. To maintain their hormone levels, the patient must take thyroid hormones for the remainder of their life.

Rarely, a patient may experience side effects such as vocal cord paralysis and damage to the parathyroid glands, which are responsible for producing calcium. Unintentional removal of parathyroid glands may result in low calcium levels and require calcium replacement therapy.

Radiofrequency ablation (RFA):
This novel method of treating thyroid nodules causes tissue necrosis and nodule shrinking. It's a minimally invasive procedure used to treat benign thyroid nodules (not malignant). RFA is generally advised for those who have not responded well to medicine or surgery.

Additional information:

Hyperthyroidism may result in female infertility:
One of the symptoms of hyperthyroidism is irregular menstrual cycles (periods), which can make it difficult to conceive. Some people first contact their healthcare provider because they are having difficulty getting pregnant and then discover they have a thyroid condition.

Hyperthyroidism while pregnancy:
During early pregnancy, your body produces more thyroid hormones than usual to help the fetus develop. These hormones are especially important to the brain and nervous system. Having slightly elevated thyroid hormone levels is normal; however, if your levels rise dramatically, your healthcare provider may need to develop a treatment plan. High thyroid hormone levels can affect both you and the fetus.

It can be difficult to diagnose hyperthyroidism during pregnancy because your thyroid hormone levels naturally rise, and other pregnancy symptoms obscure signs of hyperthyroidism.

Foods to be avoided in hyperthyroidism:

When managing hyperthyroidism, it’s essential to be mindful of your diet. Here are some guidelines on foods to consider:

• Iodine-Rich Foods: Excessive iodine can exacerbate hyperthyroidism. Limit your intake of foods high in iodine, such as seaweed, seafood, and iodized salt.

• Caffeine: While caffeine itself doesn’t cause hyperthyroidism, it can worsen symptoms. Moderation is key.

• Gluten: If you have celiac disease alongside hyperthyroidism, consider a gluten-free diet.

• Alcohol: It may affect the thyroid gland, so consume it in moderation.

• Soy Products: Soy contains isoflavones that may interfere with thyroid function.

• Fatty Foods: These can disrupt thyroid hormones.

• Sugary Foods: High-calorie, low-nutrient foods should be limited.

• Processed Foods: Watch out for excess sodium.

• Excess Fiber: It can inhibit medication absorption.

Hyperthyroidism is a form of thyrotoxicosis:

 Hyperthyroidism occurs when your thyroid gland both produces and secretes excess thyroid hormone. Thyrotoxicosis occurs when your body produces excessive thyroid hormone in general. For example, taking too much thyroid medication may result in excess thyroid hormone. This would be thyrotoxicosis, not hyperthyroidism.