[Biology Class Notes] on Thyroid Symptoms Pdf for Exam

Thyroid Malfunction

The thyroid is a butterfly-shaped gland located at the base of the neck and secretes important endocrine hormones for the body. It manufactures hormones responsible for regulating the metabolism of the body. Under certain conditions, thyroid function gets affected resulting in afflictions involving the endocrine system. Many disorders and diseases arise from the malfunctioning of the thyroid gland. These disorders occur when the thyroid produces too many hormones or too fewer hormones affecting various functions of the body.

We will look into these disorders and their symptoms in detail in this chapter.

Common Thyroid Disorders

The major thyroid abnormalities and diseases are-

1. Hypothyroidism

2. Hyperthyroidism

3. Goitre

4. Hashimoto’s Disease

5. Grave’s Disease

Hypothyroidism

When the thyroid gland produces an insufficient amount of hormone required for the body it gives rise to Hypothyroidism. It may arise from the problems in the thyroid gland, pituitary gland or the hypothalamus. Any of these malfunctions lead to low levels of hormone circulating in the body and impacting normal functions of the body.

Causes of Hypothyroidism

Hashimoto’s Disease- It is the most common cause of hypothyroidism. It is also known as an autoimmune disorder or Hashimoto’s thyroiditis. An autoimmune disorder is the one which occurs when the immune system produces antibodies which attack the body’s tissues. So, when these antibodies attack the thyroid gland, it impacts the thyroid gland’s ability to produce sufficient levels of hormones. The exact cause of this kind of trigger is unknown but it may occur due to environmental factors.

• Response to Hyperthyroidism Treatment- Sometimes treatment of Hyperthyroidism (overproduction of thyroid hormones) involves the use of radioactive iodine or anti-thyroid medicines. This measure may lower the hormone levels, turning hyperthyroidism into hypothyroidism.

• Surgery- Surgical removal of the thyroid gland partly or completely may lead to less production or no production of the hormone at all.

• Radiation- Cancer patients are given radiation therapy which may affect the thyroid gland when parts of the neck and head undergo radiation. Thus, it may lead to hypothyroidism.

• Medications- Some medicines also interfere with the activity of the thyroid like lithium. 

• Hypothyroidism- This may also occur as a result of congenital disease, pituitary disorders, pregnancy, or iodine deficiency under rare circumstances.

Symptoms of Hypothyroidism

Although hypothyroidism symptoms are barely noticeable in the beginning, as the body continues to slow on metabolism due to fewer thyroid hormones, more evident and obvious symptoms develop. These may include the following-

• Fatigue

• Poor concentration

• Increased sensitivity to cold

• Constipation

• Dry skin

• Weight gain

• Puffy face

• Hoarseness

• Muscle weakness

• Elevated blood cholesterol level

• Muscle aches, tenderness and stiffness

• Pain, stiffness or swelling in your joints

• Heavier than normal or irregular menstrual periods

• Thinning hair

• Slowed heart rate

• Depression

• Impaired memory

• Enlarged thyroid gland (goitre)

Synthetic hormone tablets or hormone therapy is suggested to treat hypothyroidism in most cases.

Hyperthyroidism

Hyperthyroidism also pertains to the overactive thyroid gland. And it results from excessive production of thyroid hormone- thyroxine. It is less common as compared to hypothyroidism. Elevated levels of thyroid hormone accelerate the body’s metabolism causing irregular weight loss, irregular heartbeat, etc.

 Causes of Hyperthyroidism

Grave’s Disease- It is another autoimmune disease, where the immune system attacks the thyroid gland and in response thyroid gland produces too much thyroxine to fight back. Grave’s disease is hereditary and runs in the family.

Other causes of hyperthyroidism include swollen thyroid gland or outgrowths on the thyroid gland called thyroid nodules.

Symptoms of Hyperthyroidism

Like hypothyroidism, initially, the signs and symptoms of hypothyroidism are also unnoticeable. But, mostly, one feels the following symptoms and may seek a doctor’s help-

• Feeling nervous, weak, tired, moody, etc.

• Shaking of hand

• Breathing problems

• Faster heartbeat

• Feeling hot, sweaty, warm

• Red and itchy skin

• Frequent bowel movements

• Hair fall, weight loss, more than usual appetite

Hyperthyroidism if remained untreated may lead to heart problems, bone problems, and a serious condition called thyroid storm which is a life-threatening condition. During a thyroid storm, individuals show dangerously high levels of heart rate, blood pressure, and body temperature.