Thyroid diseases -- types, causes, diagnosis and treatmentThe thyroid gland undoubtedly stands to be one of the most important glands of the human endocrine system. It secretes hormones that regulates metabolism and other important functions of the body and hence initiates growth and development of the same.

The thyroid gland produces two important hormones, namely, the thyroxine (T4) and the triiodothyronine (T3). Of these two hormones the T3 hormone is considered to be more crucial in maintaining the metabolism and other bodily functions. When released in the systems a large part of the T4 hormone is converted in to T3 hormone, which is a normal function of the system.

How does the thyroid gland work?

Now even though it may look simple that the thyroid gland works by just producing thyroid hormones, there is a lot happening inside the body to make this process happen. The thyroid gland is regulated by the pituitary gland, another important gland located in the brain. The pituitary gland in turn is regulated by the hypothalamus which is the part of the human brain. The hypothalamus secretes a hormone called the thyrotropin releasing hormone (TRH), which in turn sends a signal to the pituitary gland to release thyroid stimulating hormone (TSH). The TSH again signals the thyroid to release the thyroid hormones. Also read thyroid facts you need to know. 

What is thyroid disease?

If the above mentioned equilibrium is disturbed due to any reasons resulting in increased or decreased production of thyroid hormone, it causes various thyroid diseases. In addition, structural abnormalities in the gland. Also read 10 facts you should know about thyroid diseases. 

Types and causes of thyroid disease:

Since the thyroid hormones play an important part in metabolism and growth it is necessary that an optimal amount of the hormones circulate within the human system for proper functioning and nourishment. But if there is a slight increase or decrease in the levels of the hormones in the system it could lead to a medical condition that might need attention.

If there is an excess amount of thyroid hormone produced it could lead to a condition called ad hyperthyroidism and a deficit of these hormones can give rise to a condition called as hypothyroidism.

The thyroid gland also produces another hormone called the calcitonin. This hormone regulates calcium by lowering calcium levels in the blood. Excess of calcium could again give rise to another condition called hypercalcemia.

Hypothyroidism: This condition is denoted by a dip in the thyroid hormones in the blood. It happens if one has an underactive thyroid or the glands that control the thyroid malfunctions, though there are other causes also that can lead to this condition. It is usually noticed that hypothyroidism affects women more than men and gets worse as one ages. Some of the causes that could lead to a low level of thyroid hormone in the system and give rise to hypothyroidism are:

  • Hashimoto’s disease: An auto immune disease that attacks the tissues of the thyroid gland.
  • Thyroiditis: Inflammation of the thyroid gland that can result in less production of the hormone. Also read how to tackle hypothyroidism during pregnancy. 
  • Radioactive treatment for hyperthyroidism: If one is treated for hyperthyroidism with radioactive therapy, the treatment while correcting the condition can lead to an unpleasant outcome – underactive thyroid.
  • Malfunctioning of the other important glands in the system:At times one might have a perfect healthy thyroid but can still suffer from the problem of hypothyroidism, if the glands that regulate the function of thyroid go haywire.
  • Medications taken to treat hyperthyroidism: Sometimes medications that are prescribed to control hyperthyroidism can lead to hypothyroidism making the thyroid gland function sub-optimally.
  • Iodine deficiency: A diet low in iodine has been seen to be a major cause of hypothyroidism in adults. It is noticed that areas that have low sources of iodine have more number of people suffering from this condition.

Hyperthyroidism: In this condition there is an overdrive of the thyroid hormone in the blood due to an over active thyroid gland that secretes the hormones in abundance. Some of the common causes that leads to hyperthyroidism are:

  • Graves’s disease: This is the most common reason that causes hyperthyroidism in adults.
  • Nodules in the gland: A single lump or multiple lumps growing on the thyroid can mimic its function and secrete more hormones than necessary.
  • Excessive TSH secretion: Sometimes a medical condition like a tumor in the pituitary gland can initiate excess secretion of TSH that could lead to hyper secretion of the thyroid hormone leading to the condition.
  • Medications taken to treat hypothyroidism: Excessive intake of medications that initiates thyroid to produce the hormones can lead to this condition.
  • Thyroiditis: If the inflammation of the thyroid gland leads to abnormal amounts of hormones into the system, it can lead to hyperthyroidism.

Thyroid enlargement: In this condition thyroid disease occurs due to the structural changes in the gland like an enlargement or nodules appearing on the gland. There can be benign cysts developed or cancerous ones in form of nodules. Enlargement of the thyroid gland is often termed as goiter. Goiter can at times be unnoticeable and at other times, it can lead to abnormal enlargement that might need surgical removal of the organ.

Symptoms of a thyroid malfunction:

Both hypothyroidism and hyperthyroidism can have adverse affects on a person’s health. The symptoms and signs of the condition can vary from person to person depending on the severity of the condition.

Some of the common symptoms of hypothyroidism are:

  • Extreme fatigue
  • Forgetfulness and confusion in thought process
  • Feeling cold all the time
  • Repeated bouts of constipation
  • Dry skin
  • Bloating or fluid retention in the body
  • Stiffness in joints and muscles along with aches and pains
  • Menorrhagia, excessive or prolonged menstrual bleeding
  • Depression

Some of the common symptoms of hyperthyroidism are:

  • Sweating profusely
  • Intolerance to heat
  • Increased bowel movements
  • Slight tremor in the limbs
  • Rapid heart rate
  • Unexplained weight loss
  • Excessive fatigue
  • Concentration problem
  • Irregular menstrual cycle
  • It can lead to irregular heart rhythms and even heart failure in the elderly.
  • Untreated hyperthyroidism may result in condition called thyroid storm, where a person can suffer from high blood pressure, fever leading to a heart failure.
  • In Graves’ disease, there may be eye changes and skin changes in addition to the other symptoms.

Diagnosis of thyroid disease:

The diagnosis of the disease often happens in the following ways:

Blood test: The first step of the diagnosis involves a blood test to check the levels of the TSH along with the levels of T3 and T4. Lower levels would indicate hypothyroidism and the higher values would be indicative of hyperthyroidism. If cancer is suspected, a thyroglobulin level check may be asked for. In rare circumstances, the blood calcitonin level may also be checked. Also read about five tests to check thyroid function. 

Imaging techniques: This is usually done if the doctor suspects any structural changes in the gland. An ultrasound or thyroid scan can detect the presence of cysts, their nature and also the extent of thyroid enlargement that has taken place.

Biopsy: This is usually done if a cancer is suspected to study the tissues taken from the gland and if any cyst or tumour is noted in the thyroid gland.

Treatment of thyroid disease:

Medication: In case of hyperthyroidism oral medication is the first line of treatment to reduce the hyperactivity of the gland and control the levels of hormone in the body.

To treat hypothyroidism synthetic thyroid hormone is given daily to make up for the deficit in the system.

A very small amount of synthetic hormone may be given to treat goiter in order to shrink it to its previous size.

Surgery: A surgery might be suggested for a number of reasons – either to remove a diseased part of the gland, to remove nodules or cysts or to remove an enlarged gland completely to ensure proper treatment. In such a case a lifelong thyroid hormone replacement might be necessary.

A new kind of surgery that is slowly gaining ground when it comes to thyroid surgeries is robotic thyroid surgery. This kind of surgery is suggested to treat benign and cancerous nodules of the thyroid gland and is done through a cut in the armpit (axilla). This avoids a visible scar on the neck. Specially designed retractors allow the robotic arms to reach the neck region and remove the tissue. 

Radioactive ablation: This form of treatment is usually offered to treat hyperthyroidism if oral medication turns to be ineffective for the treatment. The iodine used in the therapy destroys the part of the gland that has gone on an overdrive to bring the levels of thyroid hormone to normalcy.

Read more about causes, symptoms, diagnosis and treatment of thyroid disease.

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