When the thyroid is not functioning properly, it can lead to conditions such as hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid). These conditions can cause a range of symptoms and affect various bodily functions. Understanding these conditions is essential for diagnosis and treatment, as both hypothyroidism and hyperthyroidism can have significant impacts on overall health.
What Is The Thyroid Gland?
The thyroid gland is a butterfly-shaped gland in the frontal part of the neck. This gland forms part of the endocrine system and mainly regulates the body’s metabolism. The thyroid gland releases and produces thyroid hormones known as T3 and T4. Its secretion is based upon stimulations received from the hypothalamus and the pituitary gland in the brain. When there is a disturbance in this pathway it can cause an underactivity of the thyroid gland or the opposite can happen where too much of T3 and T4 is being produced and secreted.
What Is Hypothyroidism?
Hypothyroidism is a term used to describe an underactive thyroid that is accompanied by low levels of T3 and T4.
Primary Hypothyroidism
Primary hypothyroidism is a common condition that is diagnosed when the problem is with the thyroid gland itself and where it does not produce or release sufficient amounts of T3 and T4. In these cases, T3 and T4 are lower-than-normal while thyroid stimulating hormone (TSH) levels, which are secreted from the pituitary gland, are usually elevated. This is because the body is trying to compensate for low thyroid levels and trying to restore balance.
Secondary Hypothyroidism
Secondary hypothyroidism is not as common and is diagnosed when there is something wrong with the physiology of the pituitary gland. Secondary hypothyroidism usually presents with decreased levels of TSH as well as decreased levels of T3 and T4.
Causes Of Hypothyroidism
Hypothyroidism can be caused by various key elements. An autoimmune disease known as Hashimoto’s disease attacks the thyroid cells as if they were to be a foreign body. This leads to the destruction of the thyroid and decreased levels of T3 and T4. This disease can be triggered by an infection or environmental and genetic factors.
Another element that can cause hypothyroidism is a thyroidectomy, where the thyroid is removed due to a medical reason causing now thyroid hormones to be produced. Thyroiditis, which is the inflammation of the thyroid can also cause a decrease in thyroid hormones. Certain medications such as lithium can also cause a decrease in the production and secretion of T3 and T4.
Symptoms Of Hypothyroidism
Hypothyroidism symptoms include fatigue, low energy, weight gain, cold intolerance, dry skin, brittle hair, hair loss, and a puffy face. Other signs may include hoarseness, a slow heart rate, joint pain, muscle weakness, depression, memory issues, and difficulty concentrating. Reproductive symptoms such as heavy or irregular periods and potential infertility can also occur, along with constipation. In severe cases, hypothyroidism may lead to goiter (visibly enlarged thyroid) or life-threatening myxedema.
Can Hypothyroidism Be Prevented?
Hypothyroidism, a condition where the thyroid gland produces insufficient thyroid hormones, often arises from causes that cannot always be prevented. However, certain actions can reduce the risk or help manage factors that contribute to it:
Causes That Cannot Be Prevented
Autoimmune conditions (e.g., Hashimoto’s thyroiditis) are the most common cause of hypothyroidism in many populations and are not preventable as they stem from immune system dysfunction. Congenital hypothyroidism is present at birth and also cannot be prevented.
Factors That Can Be Addressed
Various factors can be addressed to prevent hypothyroidism.
Iodine intake: Both iodine deficiency and excess can impair thyroid function. Maintaining a balanced iodine intake through diet or iodized salt can help. Be cautious with supplements to avoid overconsumption.
Avoid thyroid-damaging substances: Exposure to certain medications (e.g., amiodarone, lithium) or environmental toxins (e.g., perchlorates) can interfere with thyroid function. Consult a healthcare provider before taking medications that might impact thyroid health.
Manage stress and overall health: Chronic stress and poor health habits may contribute to autoimmune thyroid conditions. A healthy lifestyle that includes regular exercise, a balanced diet, and adequate sleep can support thyroid health.
Treatment Options
Hypothyroidism and any related cause that leads to a lower secretion of T3 and T4 can be treated with a medication that replaces the thyroxine (T4) in the body. The medication is known as levothyroxine and will enter the body as T4 thereafter it will be metabolised in the bloodstream to T3. In some severe cases such as a medical emergency, liothyronine (T3), which is the active form of the thyroid hormone, can be given. This needs to be used carefully as it works quite quickly and it has more severe side effects than those of levothyroxine.
What Is Hyperthyroidism?
Hyperthyroidism is a term used to describe an overactive thyroid which is usually accompanied by higher thyroid hormone levels of T3 and T4, however, this condition is not as common as hypothyroidism.
Primary Hyperthyroidism
Primary hyperthyroidism is usually when there is a problem with the thyroid producing too much thyroid hormone. This can cause severe effects on the body. Primary hyperthyroidism usually causes elevated levels of T3 and T4 while the TSH levels from the pituitary gland is lower than normal because the body is trying to compensate for the high thyroid levels while trying to achieve homeostasis.
Secondary Hyperthyroidism
Secondary hyperthyroidism occurs when there is a fault on the pituitary gland’s side like a TSH-producing tumours. This will increase the TSH levels as well as the T3 and T4 levels.
Causes Of Hyperthyroidism
Primary hyperthyroidism is usually caused by an autoimmune disease known as Grave’s disease. This disease is where the immune system causes an overproduction of T3 and T4 from the thyroid. Here, the T3 and T4 levels are elevated while the TSH levels from the pituitary gland are lower than normal. Grave’s disease usually presents with bulging eyes, an enlarged thyroid, and inflamed eyes while being sensitive to light.
Primary hyperthyroidism can also be caused by a cancerous tumour growth on the thyroid that increases the production of T3 and T4. Another cause includes excessive consumption of iodine through dietary intake.
Symptoms Of Hyperthyroidism
Hyperthyroidism can lead to symptoms such as weight loss despite increased appetite, fatigue, sweating, heat intolerance, and muscle weakness. It can cause a rapid or irregular heartbeat, nervousness, irritability, tremors, and difficulty concentrating. Physical signs include thinning skin, brittle hair, frequent bowel movements, and, in some cases, goiter. Eye-related symptoms like bulging eyes (exophthalmos), dry eyes, and light sensitivity are common in Graves’ disease. Reproductive effects may include irregular menstrual cycles in women and decreased libido in both sexes.
Can Hyperthyroidism Be Prevented?
Hyperthyroidism is often caused by autoimmune diseases, such as Graves’ disease, which makes complete prevention difficult. However, adopting certain strategies can help minimize risks or manage contributing factors effectively.
Iodine intake: One crucial step is maintaining a balanced iodine intake. Iodine is essential for thyroid hormone production, but excessive iodine, often from supplements, medications, or diets high in iodine-rich foods like seaweed, can overstimulate the thyroid gland, particularly in individuals with underlying vulnerabilities.
Thyroid stimulating substances: Another factor to consider is avoiding exposure to substances that can overstimulate the thyroid. Medications such as amiodarone, used for heart conditions, or lithium, used in psychiatric treatment, are known to affect thyroid function. Consulting a healthcare provider about potential side effects before starting these medications is essential, especially for individuals with a family history of thyroid disorders.
Healthy lifestyle practices: Lifestyle plays a significant role in thyroid health. Chronic stress, poor diet, and lack of sleep can weaken the immune system and contribute to the development of autoimmune diseases like Graves’ disease.
Engaging in regular exercise, maintaining a balanced diet rich in nutrients that support the thyroid (e.g., selenium, zinc, and vitamin D), and practicing stress-reducing activities like meditation or yoga can help. A well-rounded lifestyle not only supports thyroid function but also improves overall health.
Treatment Options
Hyperthyroidism can be treated with pharmacological interventions. These medications reduce the production of T3 and T4 helping to reach a balance in these hormones. An individual will typically note improvement in their condition within 3-6 months.
In severe cases known as a thyroid storm, radioactive iodine can be used to inhibit the uptake of iodine and thus reduce the production of thyroid hormones. In the case where high levels of T3 and T4 are caused by excessive consumption of Iodine, it is recommended to adjust the diet and decrease the amount of iodine consumed. Iodine is present in table salt, shellfish, and seaweed.
