Difference Between Hyperthyroidism and Hypothyroidism

Both hypothyroidism and hyperthyroidism are hormonal imbalance disorders that are caused by problems affecting the thyroid gland and its production of thyroid hormones. It is one of the most commonly encountered problems seen by endocrinologists and general physicians in their clinical practice.

As we know, the thyroid gland is a small butterfly shaped hormone producing gland in the front of the neck, and its main function is the production of the thyroid hormones that play a very important role in the normal functioning of the human body. The two hormones that are produced by the thyroid gland are Triiodothyronine or T3 and Thyroxine or T4. These hormones are essential for various body functions include

• Regulating metabolism – how the body utilizes energy obtained from food
• Regulating body temperature – by affecting the production and utilization of heat by the body
• Supporting growth and development – play an important role in the growth and development of bones and organs in children, particularly the development of the brain
• Controlling heart rate – by influencing the speed and contraction of the heart muscle
• Healthy digestion – by controlling the production and utilization of digestive enzymes
• Mood and Energy levels – and imbalances can lead to anxiety, depression, and tiredness

What are some commonly seen thyroid problems?

There are many problems that affect the thyroid gland and including overproduction of thyroid hormones or hyperthyroidism, underproduction of thyroid hormones or hypothyroidism, enlargement of the thyroid gland or goitre, development of lumps or thyroid nodules, thyroid cancers, and inflammation of the thyroid gland or thyroiditis. Among these hyperthyroidism, hypothyroidism, and goitre which may be caused either by hypothyroidism or hyperthyroidism or other thyroid problems are commonly seen in large numbers.

What is hypothyroidism?

Hypothyroidism is a condition in which the thyroid gland is unable to produce sufficient quantities of the thyroid hormones resulting in a problem with various body functions and leading to symptoms such as

• Fatigue and tiredness
• Weight gain
• Intolerance of cold
• Dry hair and dry skin
• Constipation
• Depression and low mood
• Muscle aches and stiffness
• Joint pains
• Heavy menstrual periods or irregular menstrual periods
• Infertility and low libido

Hypothyroidism can be caused by many conditions that directly affect the thyroid gland or sometimes the pituitary gland. Some common causes of hypothyroidism include

• Iodine deficiency – deficiency of iodine in the diet can lead to hypothyroidism as iodine is an essential compound that is required for the production and activation of the thyroid hormones.
• Autoimmune diseases - such as Hashimoto’s thyroiditis in which the body’s immune system produces antibodies that attack and destroy normal thyroid gland tissue resulting in an underproduction of the thyroid hormones.
• Surgery or Radiation Therapy to the thyroid – surgical procedures or radiation therapy for the treatment of other thyroid diseases such as thyroid cancer can also lead to the development of hypothyroidism
• Medications – certain medications such as lithium or amiodarone can lead to underproduction of the thyroid hormones by the thyroid gland
• Pituitary gland problems – problems with the pituitary gland can lead to a decreased production of the thyroid stimulating hormone (TSH) which results in a reduced production of the thyroid hormones
• Aging – Thyroid production decreases with age and elderly people are more prone to autoimmune diseases that can cause hypothyroidism
• Congenital thyroid gland problems – some thyroid problems present at birth result in the formation of an underactive thyroid gland, and developmental delays in these children

Although hypothyroidism can affect any gender and at any age, there are certain risk factors that increase the likelihood of developing hypothyroidism. These include

• Female gender
• Elderly age
• Family history of thyroid disease
• Pregnancy
• Iodine deficiency
• History of radiation therapy or thyroid surgery

The main treatment for hypothyroidism is through the supplementation of a synthetic thyroid hormone known as Levothyroxine which mimics the actions of the thyroid hormone T4. The dosage of Levothyroxine is adjusted based on the free thyroid hormone levels and the dosage may have to be changed from time to time as required. The tablet is taken on an empty stomach in the morning, and regular monitoring of thyroid levels is advised.

What is hyperthyroidism?

Hyperthyroidism is a condition in which the thyroid gland is producing more than the required amounts of thyroid hormones, and the excess amounts of circulating thyroid hormones affect normal body functions leading to the development of symptoms such as

• Increased appetite
• Weight loss in spite of increased appetite
• Rapid heartbeat and palpitations
• Anxiety and nervousness
• Tremors or shaking
• Increased sweating
• Increased sensitivity to heat
• Diarrhea and changes in bowel movements
• Tiredness and weakness
• Sleep trouble
• Changes in menstruation patterns

Hyperthyroidism can be caused by several conditions that directly affect the thyroid gland. Some of these causes include

• Grave’s Disease – a disease caused by abnormal immune system activity in which the thyroid gland is affected and produces excess quantities of thyroid hormones
• Thyroiditis – an inflammation of the thyroid gland resulting in an excess release of thyroid hormones into the blood
• Thyroid nodules – multiple small growths in the thyroid tissue that produce excess hormones
• Excess iodine intake – excessive intake of iodine can lead to the overproduction of the thyroid hormones
• Overactive thyroid gland – sometimes no obvious underlying cause can be found for the overactivity of the thyroid gland.

The treatment of hyperthyroidism includes is to control and manage the underlying condition that is causing excessive thyroid hormone production. The treatment may include the use of

• Medications such as propylthiouracil (PTU) or methimazole that block the activity of the thyroid hormone
• Beta blockers to control tremors, anxiety, and rapid heartbeat
• Radioactive iodine therapy to destroy some thyroid tissue and reduce the production of thyroid hormones
• Surgery – when conservative therapy is not effective or if the problem is very severe, then surgical removal of some or all of the thyroid gland. Subsequently, thyroid hormone replacement is needed in some cases.

What are the differences between hypothyroidism and hyperthyroidism?

Hypothyroidism and hyperthyroidism are two distinct medical conditions that affect the thyroid gland and have different symptoms, causes, and treatments for their management. Some of the main differences include

• Thyroid Hormone Levels – the main difference between the two conditions is the levels of the circulating thyroid hormones in the blood. In hypothyroidism, where there is an underproduction of thyroid hormones, the circulating levels are low. Whereas, in hyperthyroidism, where there is an overproduction of thyroid hormones, the circulating levels of the thyroid hormones in the blood are higher than normal.
• Symptoms – The symptoms of hypothyroidism and hyperthyroidism are markedly different. Hypothyroidism causes symptoms such as weight gain, tiredness, dry skin, constipation, cold intolerance, slow heartbeat, and depression, whereas hyperthyroidism can result in weight loss, increased sensitivity to heat, rapid heartbeat, sweating, anxiety and restlessness, and tremors.
• Metabolism – Hypothyroidism slows down metabolism and the way body utilizes energy resulting in weight gain, cold intolerance, and tiredness, whereas hyperthyroidism speeds up the body's metabolism resulting in symptoms such as weight loss, increased appetite, rapid heart rate, and intolerance to heat.
• Causes – The causes of the two conditions are also quite different. While hypothyroidism can be caused by iodine deficiency, radiation therapy, and thyroid surgery, hyperthyroidism can be caused by excessive iodine intake, thyroid nodules, Grave’s disease, etc.
• Treatment – the way both conditions are treated are also significantly different. Hypothyroidism is treated to increase levels in thyroid hormones through the intake of synthetic thyroid hormones, whereas hyperthyroidism is treated with medications that block the actions of the thyroid hormones, through radioiodine or thyroid surgery to remove thyroid tissue to prevent the production of thyroid hormones.

Are lifestyle modifications different for hypothyroidism and hyperthyroidism?

Lifestyle modifications for people with both hypothyroidism and hyperthyroidism help to improve the overall quality of life and reduce the effects of thyroid disease and any medications that are being given for its treatment. But the modifications required may be different for people with the two conditions.

• Diet – eating a balanced and healthy diet is important for both hypothyroidism and hyperthyroidism. However, people with hypothyroidism should consume an iodine rich diet and a selenium rich diet such as seaweed, seafood, iodized salt, Brazil nuts, eggs, and tuna, while those with hyperthyroidism should avoid these foods. People with hyperthyroidism should also avoid excessive intake of caffeine and alcohol.
• Exercise – regular exercise is beneficial to the overall health of the individual and in particular to the muscles and the cardiovascular system of the body. However, individuals with hyperthyroidism should avoid high impact and high intensity exercises as these can adversely impact the heart rate and put unnecessary strain on the heart; they should focus on yoga and low intensity exercises such as walking, etc. People with hypothyroidism can incorporate low and moderate intensity exercises including yoga to promote muscle strength and weight loss.
• Sleep – sleep is essential for the normal functioning of the body and is important for people with thyroid problems. Individuals with hypothyroidism will usually require more hours of sleep to combat their fatigue. Individuals with hyperthyroidism have sleep troubles and benefit from practicing good sleep hygiene such as avoiding mobile phone or screen exposure before bedtime, etc.
• Stress – Individuals with hypothyroidism and hyperthyroidism benefit from stress management. Practicing yoga, meditation, and breathing exercises are beneficial for individuals with both types of thyroid problems. Individuals with hyperthyroidism have to be a little more careful about stressful or high intensity activities that can affect their heart rate.

When the symptoms of thyroid disease are present or if there is a family history of thyroid disease, it is important to get regular medical check-ups to identify and manage the problem at the earliest. Individuals with both hyperthyroidism and hypothyroidism should get regular medical check-ups and investigations to monitor their thyroid hormone levels and take necessary steps to keep them under control, including following medical advice and lifestyle modification tips from endocrinologists.