This article is about the main differences between hypothyroidism and hyperthyroidism. It explains how to recognize these conditions and provides useful instructions to prevent them.

The thyroid gland works hard on its important task, but it’s still prone to various problems. Common thyroid problems are hypothyroidism and hyperthyroidism. These health conditions have some similarities, but they also have some major distinctions. You’ll learn more about hyperthyroidism vs. hypothyroidism further in this post.

What Is Thyroid And Why Is It Important?

The thyroid is an endocrine gland found in the front of your neck. Shaped like a butterfly, this gland makes hormones that regulate your metabolism[1]. These hormones are:

  • Thyroxine (T4)
  • Triiodothyronine (T3)

Thyroid hormones are necessary for the functioning of all cells in the body. Cells and tissues convert T4 to T3. T3 is a biologically active hormone that participates in the functions of cells and tissues.

Sometimes, the thyroid gland doesn’t do its job properly. It can decrease the production of hormones or make excessive amounts. Hormonal imbalance causes thyroid conditions. They are hypothyroidism and hyperthyroidism. Hypothyroidism is an underactive thyroid, whereas hyperthyroidism is an overactive thyroid. These conditions are manageable and treatable.

According to the American Thyroid Association:

  • Over 12% of the US population[2] will acquire a thyroid issue at some point in their lives.

  • Around 20 million Americans have some form of thyroid disorder. However, 60% of them aren’t aware of their condition.

Numbers show that:

  • Five out of 100 Americans[3] ages 12 and older have hypothyroidism

  • Hyperthyroidism affects one out of 100 Americans[4] ages 12 and older

Hyperthyroidism vs. hypothyroidism differences and symptoms will be discussed further in this post.

What Nutritional Deficiencies Cause Thyroiditis?

Thyroiditis is an inflammation of the thyroid gland. There are different types of this condition. Hashimoto’s thyroiditis is one of them. It is an autoimmune condition. Hashimoto's thyroiditis is the most prevalent cause of hypothyroidism. Why does this matter for hyperthyroidism vs. hypothyroidism? Read below.

In thyroiditis, the immune system starts attacking the body. The exact reason behind the immune system’s attack on thyroid tissues is unclear. While iodine deficiency causes hypothyroidism, it’s not associated with thyroiditis. For example, most people with Hashimoto’s thyroiditis aren’t deficient[5] in iodine.

Vitamin D deficiency may be involved. Recent evidence suggests that low vitamin D[6] is associated with autoimmune thyroid diseases Hashimoto’s thyroiditis and Graves’ disease. A survey[7] from BMC Endocrine Disorders confirmed that low vitamin D is involved in autoimmune hypothyroidism. It is unclear how a lack of vitamin D causes thyroid problems. That said, people with low vitamin D and hypothyroidism have higher insulin resistance. Elevated insulin resistance correlates with higher anti-thyroid antibodies.

It’s also useful to mention that vitamin D has a significant impact on the immune system. That’s why low levels of the sunshine vitamin are involved in autoimmune conditions.

Vitamin B12 deficiency is linked to thyroiditis, too. A comparative study[8] from Medical Principles and Practice found that vitamin B12 and vitamin D deficiencies are connected to autoimmune thyroid disease.

How Are Thyroid Problems Diagnosed?

A doctor orders several tests to identify the cause of the patient’s symptoms and diagnose thyroid disorders. These include physical exam, blood tests, and imaging tests (ultrasound). Diagnostic tests and their results perfectly demonstrate hyperthyroidism vs. hypothyroidism differences.

The blood test measures hormone levels to determine whether the thyroid works properly. The blood test can tell whether a patient has thyroid disorders or conditions associated with them. They can help diagnose:

  • Hypothyroidism
  • Hyperthyroidism
  • Hashimoto’s thyroiditis
  • Graves’ disease
  • Goiter
  • Thyroiditis
  • Thyroid cancer
  • Thyroid nodule

The doctor orders specific blood tests to diagnose thyroid-related problems. The tests check:

  • Thyroid-stimulating hormone (TSH): produced by the anterior pituitary and stimulates the production of thyroid hormones T4 and T3
  • Thyroxine (T4): The normal range in adults is 5.0 – 11.0 ug/dl (micrograms per deciliter of blood)
  • Free T4 (fT4): a type of T4 hormone that isn’t attached to a protein in the blood, normal range is 0.9-1.7 ng/dl (nanograms per deciliter of blood)
  • Triiodothyronine (T3): normal range is 100-200 ng/dl
  • Free T3 (fT3): a type of T3 hormone that isn’t bound to a protein, normal range is 2.3-4.1 pg/ml (pictograms per milliliter of blood)
  • Thyroid antibodies: to determine different types of thyroid conditions
  • Thyroglobulin: to diagnose thyroiditis

A major difference between hypothyroidism and hyperthyroidism is that high TSH means you have an underactive thyroid gland. The thyroid isn’t producing enough hormones so the pituitary keeps releasing TSH. Low TSH is a sign of hyperthyroidism. This means the thyroid is producing excessive amounts of hormones, so the pituitary stops releasing TSH[9].

In hypothyroidism, blood tests show low levels of T4 and T3. High levels of these hormones are a sign of hyperthyroidism. Also, high levels of fT4 and fT3 are a sign of an overactive thyroid, while low fT4 and fT3 are associated with an underactive thyroid gland. Effects on hormones are major hyperthyroidism vs. hypothyroidism differences.

What Are The Symptoms Of Hyperthyroidism And Hypothyroidism?

Hypothyroidism vs. hyperthyroidism symptoms are the major point of difference between these conditions. The conditions have different symptoms. However, some symptoms can appear in both. Goiter is a good example. It can affect hypothyroid and hyperthyroid people alike.

Symptoms of hypothyroidism include the following:

  • Weight gain
  • Feeling extra cold
  • Constipation
  • Hair loss
  • Decrease in sweating
  • Heavy and irregular periods
  • Brittle nails
  • Irritability and depression
  • Puffy face
  • Muscle or joint pain and weakness
  • Insomnia
  • Tiredness
  • Dry skin
  • Horace voice
  • Bradycardia (slowed heart rate)
  • Memory problems

Symptoms of hyperthyroidism are listed below:

  • Fatigue
  • Weight loss without trying
  • Increased hunger
  • Feeling extra warm
  • Diarrhea
  • Hair loss
  • Increased sweating
  • More frequent bowel movements
  • Sleep problems
  • Light and short periods
  • Nail thickening, flaking
  • Anxiety and nervousness
  • Bulging or puffy eyes
  • Muscle weakness
  • Tachycardia (fast heartbeat)
  • Arrhythmia (irregular heartbeat)
  • Heart palpitations (pounding of the heart)

When it comes to hyperthyroidism vs. hypothyroidism differences, it’s important to mention metabolism. In hypothyroid people, metabolism tends to be slow. The metabolic rate is faster in hyperthyroid individuals.

Which is Worse: Hypothyroidism vs. Hyperthyroidism?

One thyroid condition isn’t worse than the other. However, a difference between hypothyroidism and hyperthyroidism is in the prevalence. Hypothyroidism is five times more common[10] than hyperthyroidism. But, this doesn’t mean hypothyroidism is worse than an overactive thyroid gland.

Both hypothyroidism and hyperthyroidism are treatable. Hypothyroidism is relatively easier to treat. Patients need to take thyroid hormone medicine levothyroxine every day. This helps manage the symptoms they experience. Hyperthyroid people take medications such as anti-thyroid medicines and beta blockers. They may need radioiodine therapy, which may lead to hypothyroidism.

How Hypothyroidism And Hyperthyroidism Can Be Prevented?

Even though there is no guarantee that you won’t develop hypothyroidism or hyperthyroidism, there is a lot you can do to minimize the risk. Simple lifestyle tweaks can help you reduce the likelihood of thyroid problems. You may want to:

  • Quit smoking: Toxins from cigarette smoke can affect the thyroid. One such toxin is thiocyanate, which disrupts iodine uptake and may block the production of thyroid hormones. Smoking can elevate T4 and decrease TSH.

  • Eat selenium-rich foods: This mineral is necessary for the thyroid’s health and function. Nuts and seeds, mushrooms, turkey, eggs, and brown rice are good sources of selenium.

  • Boost immunity: Problems with the function of the immune system can lead to autoimmune diseases. Some of these diseases cause underactive or overactive thyroid glands. Eat immune-boosting foods such as citrus fruits.
  • Manage stress: High cortisol levels, the stress hormone, can contribute to thyroid dysregulation. To manage stress effectively, engage in relaxing activities and consider using NUU3 Keep Calm Gummies. These gummies are designed to help reduce stress and promote a sense of calm, supporting overall well-being and helping to maintain balanced thyroid function.

  • Thyroid collar during radiation: If you can’t avoid radiation, ask for a thyroid collar so that you can protect this butterfly-shaped gland.

  • Visit your doctor regularly: regular checkups at the doctor’s office can prevent hypothyroidism and hyperthyroidism. The doctor identifies changes and tracks test results to determine whether problems are present.

  • Manage stress: high cortisol (stress hormone) can contribute to thyroid dysregulation[11]. Make sure to manage stress by engaging in relaxing activities.

Is it Possible To Lose Unwanted Weight With Hypothyroidism And Hyperthyroidism?

Yes, it is possible to lose unwanted weight gain with thyroid disorders. Hypothyroidism vs. hyperthyroidism symptoms manifests themselves through weight changes. You may think it’s impossible to lose weight that you gain due to thyroid problems. However, that isn’t correct. Losing weight is challenging, not impossible.

  • Hypothyroid people can slim down[12] with dietary modifications, stress management, and physical activity. Check hormone levels regularly. It’s useful to manage underlying health conditions too. For example, a person with diabetes should manage their condition to lose the weight they gained due to hypothyroidism. Try Nuu3 ACV Gummies which can help in healthy weight loss.

  • One study[13] found that levothyroxine therapy for hypothyroidism led to a significant decrease in body weight. Also, it increased resting energy expenditure. Weight changes could be due to the excretion of excess body water.

People may start losing weight within three to six months after hitting the optimal dose of medication for hypothyroidism.

Frequently Asked Questions

Can Hyperthyroidism Become Hypothyroidism?

Yes, hyperthyroidism may cause hypothyroidism. This is yet another important hyperthyroidism and hypothyroidism difference. Hyperthyroidism can lead to hypothyroidism due to treatment with anti-thyroid medication such as methimazole. This medication may decrease the thyroid’s ability to produce hormones[14]. This causes a lack of thyroid hormones and may lead to hypothyroidism. Radioiodine therapy for hyperthyroidism can lead to hyperthyroidism. It works by destroying thyroid tissues and may cause an underactive thyroid gland.

Are Hyperthyroidism And Hypothyroidism Permanent?

These conditions are not necessarily permanent. However, it depends on the cause. It is possible to reverse many cases of hypothyroidism vs. hypothyroidism symptoms. These include:

  • Medications
  • Autoimmune conditions
  • Pregnancy
  • Excessive or insufficient iodine intake

Sometimes hyperthyroidism is treated by destroying the thyroid issue or removing of thyroid gland. In these cases, a person can develop permanent hypothyroidism.

What happens if the thyroid is not treated?

If the thyroid problem isn’t treated, the risk for various complications and health conditions increases. Complications of hypothyroidism include:

  • Goiter
  • High levels of LDL (bad) cholesterol
  • Cardiovascular problems
  • Birth defects
  • Damage to the peripheral nerves
  • Kidney disease
  • Cognitive issues
  • Myxedema (coma)
  • Fertility struggles

Complications associated with hyperthyroidism are:

  • Heart problems
  • Osteoporosis
  • Vision problems (thyroid eye disease)
  • Swollen, discolored skin
  • Thyrotoxic crisis

Both conditions can be managed effectively. There’s a lot you can do to manage the symptoms you cause. For instance, to address problems with hair, skin, and nails, it’s useful to try natural products like Nuu3 Hair, Skin & Nail Gummies.

Can Hypothyroidism And Hyperthyroidism Cause Infertility?

Yes, both conditions can cause infertility. Thyroid conditions affect ovulation. That’s why they may cause fertility struggles[15]. Low thyroid hormone can impair the release of an egg from the ovary. This impairs fertility. Underlying causes of hypothyroidism can contribute to infertility too. These causes include pituitary or autoimmune disorders.

The difference between hypothyroidism and hyperthyroidism is in the way they cause infertility. Hyperthyroidism increases hormone prolactin. It also raises the protein sex hormone binding globulin (SHBG). This prevents ovaries from releasing eggs. See a doctor and discuss fertility struggles if you have a thyroid disease, but want to conceive.

Concluding Remarks

Thyroid diseases are common, but they are manageable. Hyperthyroidism vs. hypothyroidism differences are in the causes, symptoms, and impact on metabolism. These disorders share some similarities too. See a doctor regularly to prevent or manage these conditions more effectively.



Dr. Ahmed Zayed

Dr. Ahmed Zayed

Dr. Zayed, has years of experience in the field and has been contributing to public health awareness. Dr. Ahmed Zayed holds a baccalaureate of Medicine and Surgery. Egypt. Dr. Zayed believes in providing knowledgeable information to readers. His articles were featured on many websites like HuffingtonPost, Chicagotribune . Other than his passion for writing, Dr. Zayed spends his time outside the hospital, either reading or at the gym.

Written by Dr. Ahmed Zayed

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