HYPOTHYROIDISM vs HYPERTHYROIDISM: Understanding the common differences

hypo versus hyperthyroidism

The thyroid is a simple bi-lobed endocrine gland.

It sits exactly at the center of the neck and releases a certain amount of thyroid hormones to regulate the whole body’s metabolism.

thyroid gland

When a thyroid gland is affected by a certain disease, the disease further develops to cause either hyperthyroidism (overproduction of thyroid hormone) or hypothyroidism (less production of thyroid hormone).

What is Hyperthyroidism?

Hyperthyroidism is an overactive thyroid that produces excess thyroid hormone and can cause body functions to speed up and may give the symptoms like an increased heart rate, palpitations, or high blood pressure.

What is Hypothyroidism?

Hypothyroidism is an underactive thyroid that produces less than the required thyroid hormone and can result in body functions slowing down, which can make the patient feel sluggish and tired.

Which is more common…Hyperthyroidism or Hypothyroidism?

Hypothyroidism is more common than hyperthyroidism.

Both conditions can be caused by an autoimmune disease, though there are other potential causes also, which will be discussed here.

This blog will deal with the comparative analysis of the symptoms, causes, complications, and treatments of hyperthyroidism and hypothyroidism.

Symptoms of Hyperthyroidism vs. Hypothyroidism

Disorder of the Thyroid Gland

The early warning signs of thyroid problems can be easy to mistake for other health conditions. Fatigue, for example, is often experienced by people in menopause. There are a few symptoms; however, that, taken together, can alert you that it’s time to see a healthcare provider:

  • Fatigue, or tiredness that doesn’t go away after a good night’s sleep
  • Weight loss or gain
  • Your resting heart rate speeds up or slows down
  • You’re more sensitive to hot or cold temperatures
Symptoms of Hypothyroidism and Hyperthyroidism

Symptoms of Hypothyroidism

  • Fatigue
  • Weight gain
  • Feeling extra cold
  • Constipation
  • Hair loss
  • Decrease in sweating
  • Heavy and irregular periods
  • Slow heart rate
  • Brittle nails
  • Irritability and depression
  • Puffy face
  • Muscle or joint pain
  • Insomnia

Symptoms of Hyperthyroidism

  • Fatigue
  • Weight loss or gain
  • Feeling extra warm
  • Diarrhea
  • Hair loss
  • Increased sweating
  • Light and short periods
  • Racing or pounding heart
  • Nail thickening, flaking
  • Anxiety and nervousness
  • Bulging or puffy eyes
  • Muscle weakness
  • Insomnia

Causes of Thyroid Disease

Thyroid disease is common. In the United States, it affects an estimated 20 million people. Up to 60% of those who have thyroid disease are undiagnosed.

The thyroid gland is a butterfly-shaped organ that produces hormones. Two of these hormones, triiodothyronine (T3) and thyroxine (T4), regulate your metabolism, help your heart, brain, and other organs function, and have a major impact on almost every cell in your body.

The thyroid is regulated by the pituitary gland in the brain. This gland produces a hormone called thyroid-stimulating hormone (TSH) to tell the thyroid to make more T3 and T4. When any part of this system is damaged or malfunctioning, the thyroid can produce either too little or too much T3 and T4. This can cause body-wide symptoms.

Causes of Hypothyroidism and Hyperthyroidism

Causes of Hypothyroidism

  • Autoimmune disease
  • Surgical removal
  • Radiation treatment
  • Congenital problem
  • Thyroiditis
  • Certain medications
  • Abnormal iodine levels
  • Pituitary gland damage
  • Rare diseases

Causes of Hyperthyroidism

  • Autoimmune disease
  • Nodules
  • Thyroiditis (temporary)
  • Overmedication
  • Abnormal iodine levels

Hypothyroidism Causes

Possible causes of hypothyroidism include:

  • Autoimmune disease: This includes Hashimoto’s disease and atrophic thyroiditis. They’re the most common causes of a hypoactive thyroid.
  • Surgical removal: Sometimes, all or part of the thyroid gland is removed as a treatment for thyroid cancerthyroid nodules, or Graves’ disease.
  • Radiation treatment: This treatment for certain cancers, Graves’ disease, and thyroid nodules can damage the thyroid gland and impair its function.
  • Congenital problem: Rarely a baby is born with a partial or missing thyroid gland or other abnormalities that impair thyroid function.
  • Thyroiditis: This is inflammation of the thyroid caused by a viral infection or atrophic thyroiditis.
  • Certain medications: In people with a genetic predisposition, drugs that may trigger hypothyroidism include Pacerone (amiodarone)Lithobid (lithium), Intron A (interferon α), Proleukin (aldesleukin or interleukin-2), and checkpoint inhibitors like Yervoy (ipilimumab).
  • Abnormal iodine levelsIodine is a crucial component of thyroid hormones, so if your body doesn’t get enough from the foods you eat, it can’t keep thyroid hormones in balance.
  • Pituitary gland damage: If it’s damaged by a tumor, radiation therapy, or surgery, the pituitary gland’s control over the thyroid may be impaired and lead to a deficiency of thyroid hormones.
  • Rare disorders: These include amyloidosissarcoidosis, and hemochromatosis. Each one deposit substances in the thyroid that shouldn’t be there and can impair its function as a result.

Hyperthyroidism Causes

Hyperactive thyroid has fewer potential causes. It may run in families. Other causes include:

  • Autoimmune disease: Graves’ disease is behind more than 70% of hyperactive thyroid cases. Damage to the thyroid is caused by antibodies that chronically activate the thyroid and lead to hormone overproduction.
  • Nodules: Abnormal growths of thyroid tissues can lead to excess hormone secretion.
  • Thyroiditis: When thyroiditis first strikes, it can cause the thyroid to release all the hormones it has produced, leading to temporary hyperthyroidism. After that, levels drop into the hypothyroid range.
  • Overmedication: If you take too much thyroid hormone medication for hypothyroidism, it can lead to hyperthyroidism.
  • Abnormal iodine levels: If you’re iodine deficient and suddenly increase your iodine intake, you may develop temporary hyperthyroidism while your body adjusts to the change.

Possible Complications of HYPOTHYROIDISM–

  • Goiter
  • Pregnancy problems
  • Peripheral neuropathy
  • Anemia
  • High cholesterol
  • Muscle disease
  • Myxedema coma

If hypothyroidism remains untreated or undertreated, it may lead to some complications:

  • Goiter: An enlarged thyroid gland may feel like a lump in your throat. Large goiters may be tender and swollen, and neckties and scarves may be uncomfortable to wear. In rare cases, goiters can make it difficult to swallow or breathe.
  • Pregnancy problems: Irregular menstrual cycles can lead to infertility. Additionally, hypothyroidism increases the risk of miscarriage, placental abruption, early delivery, and death of the baby.
  • Peripheral neuropathy: Nerve damage, potentially from fluid retention and swelling, leads to numbness, tingling sensations, weakness, and hypersensitivity to touch or temperature.
  • Anemia: Thyroid hormone deficiency impairs your bone marrow‘s production of red blood cells, leading to anemia. Symptoms include fatigue, pale skin, fast or irregular heartbeat, faintness, and shortness of breath.
  • High cholesterol: Your body cannot process cholesterol properly, which can cause high levels of LDL and total cholesterol.
  • Muscle disease: Muscle pain and stiffness, possibly accompanied by muscle weakness, can have a major impact on your functionality and daily life.
  • Myxedema coma: This is a rare and potentially fatal consequence of severe hypothyroidism triggered by infection, heart problems, or other physical stressors. Symptoms include low body temperature and blood pressure, slow heart rate, and unresponsive due to poor function of multiple organs.

Possible Complications of HYPERTHYROIDISM–

  • Goiter
  • Pregnancy problems
  • Neonatal hyperthyroidism
  • Osteoporosis
  • Atrial fibrillation
  • Thyroid storm

Hyperthyroidism Complications

  • Goiter: As in hypothyroidism, a goiter causes the feeling of a lump in your throat, may be painful, and may impair swallowing or breathing.
  • Pregnancy problems: Moderate-to-severe hyperthyroidism can lead to preeclampsia, early delivery, small babies, stillbirth, and possibly birth defects.
  • Neonatal hyperthyroidism: When the person carrying a baby has Graves’ disease, their infant may be born with hyperthyroidism or even develop it before birth. This can cause low birth weight, unusually small heads, fast heartbeat, irritability, poor sleep, and rarely, a dangerous accumulation of fluid (fetal hydrops).
  • Osteoporosis: Weak bones make you more prone to fractures.
  • Atrial fibrillation: This abnormal heart rhythm can lead to heart failure or stroke.
  • Thyroid storm: This rare but potentially deadly condition can be triggered by a combination of untreated hyperthyroidism and infection, surgery, or trauma. It includes an extremely fast heart rate, high fever, agitation, diarrhea, delirium, and possibly decreased consciousness.


Your thyroid can produce too much or too little of the hormones that are essential to normal bodily function. Each has different causes, symptoms, and treatments.

However, since thyroid hormones regulate your metabolism, both conditions can affect many parts of your body.

Leave a Reply

Your email address will not be published. Required fields are marked *