Thyroid Disease

Last updated date: 28-Aug-2023

Originally Written in English

Thyroid Disease

Thyroid Disease


Your thyroid gland generates thyroid hormone, which regulates numerous bodily functions, including how quickly you burn calories and how rapidly your heart beats. Thyroid disorders cause the gland to produce either too much or too little hormone. You may feel restless or exhausted all the time, or you may lose or gain weight, depending on how much or how little hormone your thyroid produces. Thyroid illness affects women more than males, especially after pregnancy and after menopause.


What is Thyroid Disease?

Thyroid Disease Definition

Thyroid-related medical diseases are quite frequent. Because the symptoms of hyper- or hypothyroidism are vague, they are frequently misdiagnosed as other medical or psychological illnesses. Furthermore, the signs and symptoms may grow over such a lengthy period of time that friends, family, and even personal physicians become accustomed to the changes and fail to detect any irregularities. Both disorders tend to make it difficult for the patient to operate regularly at work or at home, and they eventually require medical treatment. In the elderly, these illnesses are difficult to identify.

Thyroid disease diagnosis is extremely beneficial to the patient. Hyperthyroidism and hypothyroidism can be exceedingly debilitating. Graves' disease can lead to a thyroid storm. Blindness may result from the accompanying ophthalmopathy. The squandering of the hypermetabolic state is coupled with severe weakness. Hypokalemic periodic paralysis may be accompanied with significant periodic muscular weakness in Orientals but also in other cultures.

It is treated with beta-blockers and by reversing hyperthyroidism. Pregnancy complications caused by Graves' illness are connected with greater fetal wastage. Hypothyroidism, on the other hand, has been linked to central respiratory failure. Pericardial effusion may develop, resulting in pericardial tamponade. Infertility or hypertension may be caused by undiagnosed hypothyroidism. It has the potential to induce severe depression. Because of the hypercholesterolemia it causes, it most likely hastens the course of atherosclerosis. Autoimmune thyroiditis is more frequently connected with other autoimmune disorders, such as Type I diabetes mellitus.

Although the majority of thyroid illnesses are chronic and frequently incapacitating, they are curable. A variety of medications are available to control the signs and symptoms of hyperthyroidism, including those that control the sympathetic stimulatory effects of thyroid hormone (beta-sympatholytic drugs such as propranolol), those that control thyroid hormone uptake and synthesis (propylthiouracil, methimazole, iodide, or lithium), those that decrease its release (iodide), and those that decrease the conversion of T4 to T3 in peripheral tissues (propylthiouracil, propranolol, and glucocorticoids).

Hyperthyroidism and diffuse thyroid carcinoma can both be treated with radioiodide. Surgery is also beneficial in treating both illnesses, however it is less commonly employed in thyrotoxicosis due to the availability of effective medicines and radioiodide. Thyroid hormone replacement treatment is effective and reasonably affordable in hypothyroidism.

Thyroid dysfunction symptoms are vague yet responsive. Thus, whereas hypothyroidism usually causes weight gain, constipation, and cold intolerance, only a few people who complain of obesity, constipation, or cold intolerance are hypothyroid. Nonetheless, each additional complaint increases the likelihood of such a diagnosis, especially if physical signs indicative of hypothyroidism are also present. The laboratory provides further corroborating data, such as a low total T4 and an increased TSH, showing primary thyroid dysfunction. Similarly, hyperthyroidism symptoms are individually sensitive, but only in aggregate are they specific.


Thyroid gland physiology 

Thyroid gland physiology 

Understanding thyroid illness and interpreting thyroid function tests necessitates a knowledge of hypothalamic-pituitary-thyroid feedback regulation. It also necessitates an understanding of thyroid hormone transit and cell responses to non-protein-bound thyroid hormone. The hypothalamic hormone thyrotropin releasing hormone (TRH) regulates pituitary thyroid stimulating hormone release (TSH). TSH stimulates thyroid hormone synthesis by interacting with particular receptors on thyroid follicular cells.

T4 and T3 are carried in the blood through serum proteins. The remaining T3 generation (80%) is derived from the conversion of T4 in peripheral tissues. The most active type of thyroid hormone is T3. Non-protein-bound thyroid hormones penetrate peripheral cells and interact with a particular nuclear binding protein, constituting a tiny proportion of total circulating thyroid hormones. This connection causes the stimulation of several enzymes, which then express the influence of thyroid hormones.

The pituitary gland and perhaps the brain sense circulating levels of T4 and T3 in order to control TSH release and so keep blood levels of thyroid hormones within normal ranges. Disturbances in many elements of this complex system might present the clinician with clinical and laboratory results of hyperthyroidism or hypothyroidism, goiter, or apparent abnormalities in thyroid function tests that have no specific clinical implications. The discordance between clinical findings and laboratory tests frequently makes thyroid diseases diagnosis complex and stimulating.

Noniatrogenic causes of thyroid dysfunction include:

  • Inflammation (acute or subacute thyroiditis),
  • Autoimmune disease (Hashimoto's thyroiditis and Graves' disease),
  • Inherited metabolic defects (mono- and di-iodotyrosine deiodinase deficiency), 
  • Malignancy (follicular, papillary, anaplastic, and parafollicular or C cell), and
  • Nutritional deficiencies (iodine or protein deficiency).

Thyroid disorders can also be caused by medicinal or surgical treatments for the thyroid gland, or by the treatment of nonthyroid illnesses. Hypothyroidism following radioactive iodine or surgery for Graves' disease is one example, as is thyroid cancer after x-ray treatment to the head or neck. Following the treatment of arrhythmias with Amiodarone, which includes iodine, hypothyroidism and hyperthyroidism have been documented.

Although thyroid gland enlargement may indicate thyroid illness, physiologic and transient thyroid gland enlargement associated with pregnancy and adolescence is normal. It is occasionally mistaken with abnormal enlargement and must be considered when making a goiter diagnosis.

The thyrotoxic patient exhibits signs and symptoms associated to the metabolic consequences of excess thyroid hormone, many of which appear to be connected to increased sympathetic nervous system activity. Non-thyroid-related causes of real or perceived hypermetabolism and sympathetic overactivity, such as pheochromocytoma, cocaine usage, and nonspecific anxiety, must be distinguished. The use of beta-sympathomimetic blocking medications in the treatment of thyrotoxicosis alleviates many of the symptoms associated with the sympathetic nervous system without reducing, at least temporarily, the increased oxygen consumption associated with the hypermetabolic state.


Symptoms of thyroid disease  

Symptoms of thyroid disease

Patients with thyroid gland function or anatomical issues seek medical care for a variety of reasons. They manifest with symptoms caused by the physiologic consequences of elevated or reduced thyroid hormone plasma concentrations (hyperthyroidism or hypothyroidism, respectively). They may also exhibit indications of localized or widespread gland enlargement (diffuse goiter, multinodular goiter, or single thyroid nodule). These alterations might be the result of functional problems or benign or malignant neoplasia.

The symptoms listed below are common issues that may eventually be recognized as various thyroid illnesses or syndromes. Weight loss, anxiety or uneasiness, increased perspiration, tremulousness, diarrhea, palpitations, muscle weakness, heat intolerance, or a history of therapy for a "overactive" thyroid may be symptoms of hyperthyroidism (thyrotoxicosis). Typical symptoms of hypothyroidism include tiredness, weight gain, depression, lethargy, dry skin, cold sensitivity, voice change, change in menstruation, muscular cramps, or therapy of a thyroid issue.

Thyroid enlargement (goiter) can occur alongside hyper- or hypothyroidism. It can also happen in patients who have normal thyroid hormone production (euthyroid patient). Thyroid enlargement is commonly associated with widespread neck swelling (diffuse goiter), neck mass (uninodular or multinodular goiter), dysphagia, neck discomfort, or hoarseness. Finally, individuals who have no complaints but have "abnormal thyroid function tests" may be directed for a search for symptoms and indicators of thyroid malfunction.

Thyroid storm is an increasingly rare but still very deadly type of thyrotoxicosis characterized by significant temperature increase and/or change in mental state, ranging from intense agitation to coma, in addition to the usual symptoms of hyperthyroidism. Hypothyroid crisis is a severe thyroid hormone shortage characterized by hypothermia and obtundation.


What type of thyroid problems are there?

type of thyroid problems

The main types of thyroid problems are:

  • Hyperthyroidism: occurs when the thyroid is hyperactive and produces an excessive amount of thyroid hormone. Feeling worried or agitated, being unable to handle heat, having heart palpitations, feeling exhausted, and losing weight while consuming the same amount of food are the most typical symptoms of hyperthyroidism. Thyrotoxicosis is another term for hyperthyroidism.
  • Hypothyroidism: is a condition in which the thyroid gland is underactive and does not produce enough thyroid hormone. Hypothyroidism can be present for years without causing any symptoms. When symptoms do occur, they can be fairly diverse, including exhaustion, inability to tolerate low temperatures, constipation, dry skin, weight gain, impaired memory, and depression.
  • Thyroid cancer: Occurs when certain thyroid cells become malignant. Thyroid cancer affects more women than males and is typically detected in persons in their fifties. It is typically treated effectively.

Other thyroid issues include thyroid nodules, an inflammatory thyroid, and an enlarged thyroid (goitre). These disorders can result in hyperthyroidism or hypothyroidism.

Because the thyroid gland is responsible for many of the body's processes, it can create major health concerns if it is not working properly. It's critical to consult your doctor if you suspect you have a thyroid condition.

A doctor may undertake a physical exam after reviewing a person's symptoms and family history. This exam may involve examining for edema in the thyroid gland region, assessing the patient's heart rate, and testing their reflexes.

As part of the diagnosis, doctors may do blood testing. Thyroid-stimulating hormone (TSH) and thyroxine levels in the blood will be measured. Thyroxine is a thyroid hormone produced by the gland. Low thyroxine levels in the blood suggest hypothyroidism.

TSH is produced by the body to instruct the thyroid gland to produce thyroid hormones. When the body detects low thyroid hormone levels, it produces more TSH, therefore a high TSH level usually implies hypothyroidism.




Hyperthyroidism is a less prevalent condition than hypothyroidism in which thyroid hormone is produced in excess. Hypothyroidism symptoms are typically associated with increased metabolism. In mild situations, there may be no visible signs.

Symptoms and signs of hyperthyroidism can include:

  • Tremor
  • Nervousness
  • Fast heart rate
  • Fatigue
  • Intolerance for heat
  • Increase in bowel movements
  • Increased sweating
  • Concentration problems
  • Unintentional weight loss

Some of the most common causes of hyperthyroidism are:

  • Graves' disease
  • Toxic multinodular goiter
  • Thyroid nodules that overexpress thyroid hormone (known as "hot" nodules)
  • Excessive iodine consumption


As a short-term therapy for hyperthyroidism, a doctor may offer beta-blockers. Beta-blockers inhibit some of the thyroid hormone's actions and help alleviate symptoms such as a quick pulse and tremors. A doctor may also recommend a more permanent therapy, according to the American Thyroid Association, which includes:

  • Antithyroid drugs: These drugs can stop the thyroid from making so much thyroid hormone.
  • Radioactive iodine tablets: When a person ingests these tablets, thyroid cells absorb the iodine. This treatment then destroys them, and the gland’s hormone overproduction stops.
  • Surgery: A surgeon may remove a part, or all, of a person’s thyroid.

If a person receives radioactive iodine or has surgery, their thyroid may no longer generate adequate hormones, resulting in hypothyroidism. In this case, they would require thyroid hormone replacement therapy.




Hypothyroidism occurs when the thyroid gland produces inadequate thyroid hormone. It can result from thyroid, pituitary, or hypothalamic gland dysfunction.

Symptoms of hypothyroidism can include:

  • Fatigue
  • Poor concentration or feeling mentally "foggy"
  • Dry skin
  • Constipation
  • Feeling cold
  • Fluid retention
  • Muscle and joint aches
  • Depression
  • Prolonged or excessive menstrual bleeding in women

Some common causes of hypothyroidism include:

  • Hashimoto's thyroiditis (an autoimmune condition that causes inflammation of the thyroid gland)
  • Thyroid hormone resistance
  • Other types of thyroiditis (inflammation of the thyroid), such as acute thyroiditis and postpartum thyroiditis


  • Diagnosis of Hypothyroidism

To diagnose hypothyroidism, doctors will largely utilize blood testing. Prior to this, they may search for physical indications such as a noticeably enlarged thyroid, a quick pulse, and finger tremors.

Blood testing, as with hypothyroidism, will primarily assess thyroid hormone and TSH levels. In hyperthyroidism, the quantity of thyroid hormone in the blood is lower than normal, causing the body to produce more TSH. If both of these outcomes are shown by tests, a doctor may be able to identify the disease.

  • Hypothyroidism Treatment

Treatment for hypothyroidism centers on thyroid hormone supplementation. Doctors cannot now treat hypothyroidism, although they can help individuals control it in the majority of instances.

  • Synthetic thyroxine

Doctors typically administer synthetic thyroxine, a drug that is comparable to the T4 hormone, to restore levels. Doctors may advise taking this every morning before eating.

The patient's history, symptoms, and current TSH level are used to decide dosage. Doctors will check the patient's blood on a frequent basis to see whether the synthetic T4 dosage has to be altered. Regular monitoring will be necessary, but the number of blood tests will most likely reduce over time.

  • Iodine and nutrition

Iodine is a mineral that is required for thyroid function. Iodine deficiency is one of the most prevalent causes of goiter, or abnormal thyroid gland growth. Most individuals need to have enough iodine, but persons with autoimmune thyroid disease are especially susceptible to the effects of iodine, which can cause or aggravate hypothyroidism. If they are susceptible to the effects of iodine, they should notify their doctor.

People with hypothyroidism should consult their doctor before making large dietary changes, especially when beginning a high fiber diet or consuming a lot of soy or cruciferous vegetables. Diet can influence how well thyroid medication is absorbed by the body.

Iodine needs rise during pregnancy. Iodized salt in the diet and prenatal vitamins can help to maintain adequate iodine levels. Following the counsel of a trained healthcare practitioner, hypothyroidism may usually be controlled correctly. Thyroid hormone levels should return to normal with adequate therapy. In most situations, hypothyroidism drugs must be used for the remainder of the patient's life.


Thyroid nodules

Thyroid nodules

Thyroid nodules are lumps that can occur alone or in clusters on a person's thyroid. Thyroid nodules are rather frequent. According to estimates, over 50% of persons over the age of 60 have a thyroid nodule. The great majority of thyroid nodules, on the other hand, are completely benign.

It is unknown what causes thyroid nodules. Thyroid nodules do not usually produce symptoms, although they can induce hyperthyroidism if they become hyperactive. During an examination, a doctor will be able to feel thyroid nodules on a person's neck. If they find nodules, doctors may run tests to see if you have hyperthyroidism or hypothyroidism.

According to a 2015 study, thyroid cancer is found in 7-15 percent of thyroid nodule patients. To screen for cancer, physicians may use an ultrasound or a fine-needle biopsy during the diagnosing process.

A doctor will advise removing the nodules if there are any indicators of malignancy or potential risk of cancer. A doctor may remove part or all of the gland depending on the kind of cells identified in a biopsy and the likelihood of the nodule being cancerous.


What is Thyroid cancer?

Thyroid cancer definition

Thyroid cancer develops when cancer cells grow in thyroid gland tissues. The majority of persons with thyroid cancer have a thyroid nodule that causes no symptoms. If you do experience symptoms, you may experience swelling or a bump in your neck. The bump may make swallowing difficult. Your doctor will arrange tests to determine whether the lump or nodule is malignant. The majority of thyroid nodules are not malignant.

Who is at risk for thyroid cancer?

Thyroid cancer affects women three times more than males. Thyroid cancer is becoming more common in women. The number of women diagnosed with thyroid cancer is anticipated to more than double by 2020, from 34,000 to more than 70,000. 

Thyroid cancer is more common in women who: 

  • Are between the ages of 25 and 65
  • Had radiation therapy to the head or neck, especially in childhood, to treat cancer
  • Have a history of goiter
  • Have a family history of thyroid cancer


  • How is thyroid cancer treated?

Thyroid cancer is often treated by surgery to remove the entire thyroid gland or as much of it as can be safely removed. If the cancer is tiny and has not progressed to the lymph nodes, surgery alone can cure it.

Following surgery, your doctor may additionally utilize radioiodine treatment. Thyroid cancer cells that were not eliminated after surgery or that have migrated to other regions of the body are destroyed by radioiodine treatment. Your doctor may also discuss various thyroid cancer therapies with you.


How do thyroid problems affect women?

Thyroid illness

Thyroid illness is more common in women than in males. One in in eight women will experience thyroid issues over her lifetime. Thyroid disorders in women can result in:

  • Problems with your menstrual period. Your thyroid regulates your menstrual cycle. Too much or too little thyroid hormone might cause irregular or light menstruation. Thyroid illness can also cause your periods to halt for many months or longer, which is known as amenorrhea. Other glands, including your ovaries, may be affected if your body's immune system causes thyroid illness. This can result in early menopause (before age 40).
  • Problems getting pregnant. When thyroid dysfunction interferes with the menstrual cycle, it also interferes with ovulation. This may make it more difficult for you to conceive.
  • Problems during pregnancy. Thyroid problems during pregnancy can cause health problems for the mother and the baby.

Thyroid symptoms are sometimes confused with menopausal symptoms. Thyroid disorders, particularly hypothyroidism, is more common after menopause.



The thyroid is a gland located in the neck that regulates several of the body's most vital activities. You may face a variety of health issues if your thyroid becomes hyperactive (hyperthyroidism), underactive (hypothyroidism), or malignant.

Hyperthyroidism occurs when the thyroid gland generates an excessive amount of thyroid hormone. This raises a person's metabolic rate and can cause a rise in heart rate, elevated blood pressure, and weariness. Hypothyroidism, on the other hand, occurs when the thyroid gland produces insufficient hormone. This reduces the body's metabolism and might cause fatigue, chilly sensations, and constipation. Thyroid disorders, on the other hand, are typically treatable once they are identified.