Overactive Thyroid Gland (Hyperthyroidism) Symptoms, Causes And Treatment

By -

Hyperthyroidism is a glandular disorder where your thyroid gland produces and releases more of its hormone than the human body requires. This is also commonly referred to as ‘overactive thyroid disease’ or simply as an overactive thyroid gland.

This is not a disease to be ignored because your thyroid, located at the front of your neck, produces hormones that affect nearly every part of the human body including your muscles, brain and skin. These glands control the way in which your body uses energy, which means it affects your metabolism and how your body uses the calories you consume.

Thyroid-Gland-Location

This photo shows where the thyroid gland is located.

Hyperthyroidism Symptoms

Symptoms of hyperthyroidism vary depending on exactly how much excess hormone is being released, the age and overall health of the patient.

Common Symptoms of Hyperthyroidism
  • Weight loss or gain without reason
  • Nervous and general irritability
  • Increased appetite
  • Impaired fertility
  • Insomnia or other sleep disturbances including sleeping too much
  • Reduced menstrual flow
  • Fatigue
  • Muscle weakness
  • Heat intolerance
  • Uncontrollable sweating
  • Swelling in lower leg
  • Sudden paralysis
  • Shortness of breath
  • Enlarged thyroid
Symptoms of Hyperthyroidism in Older Patients

Older patients suffering from hyperthyroidism will not always present with any symptoms or very subtle ones. Those who do will experience common symptoms in addition to:

  • Heart failure
  • Heat intolerance
  • High blood pressure
  • Delirium
  • Fever
  • Increased heart rate
  • Confusion
Neurological Manifestations of the Disease

Many symptoms of an overactive thyroid gland are neurological, which means they have an effect on the nervous system. Some of these symptoms are common and others will only effect specific populations. Neurological symptoms of hyperthyroidism are:

  • Anxiety and irritability
  • Insomnia or hypersomnia
  • Visual problems including blurry vision or light sensitivity
  • Tremors
  • Excessive Sweating
  • Cognitive impairment/dysfunction
Specific Symptoms of Graves’ Disease

People suffering from hyperthyroidism as well as Graves’ disease may also experience a symptom known as ‘pretibial myxedema’ which simply is fluid build-up in the tissues surrounding the shin bone. Those without Graves’ disease may also experience this symptom but it is far less likely.

There are other Graves’ Disease symptoms associated with hyperthyroidism that affect the eyes. If you smoke these symptoms are much likely to present. Some symptoms of Graves’ ophthalmopathy are:

  • Swollen, red eyes
  • Protruding eyeballs
  • Light sensitivity
  • Inflammation of the eyeball
  • Reduced eye movement
Minor Ocular Symptoms

Some patients with hyperthyroidism but not Graves’ disease may also experience certain ocular symptoms. These changes in vision may be mild or severe depending on how excessive the hormone release is. Some of these ocular signs and symptoms of hyperthyroidism are:

  • Photophobia (light sensitivity)
  • Double vision (diplopia)
  • Irritated eyes with excess tears
  • Eyeball protrusion

Causes

There are numerous health problems and conditions that can cause the thyroid gland to produce too many hormones. If you have any of the following conditions you may be at risk for hyperthyroidism:

  • Graves’ Disease is an autoimmune disease that creates an antibody that makes the thyroid overactive. This disease is hereditary and it primarily affects young women.
  • Plummer’s Disease occurs when a lump or nodule in the thyroid becomes overactive and produces too much hormone.
  • Thyroiditis is when an inflammation of the thyroid gland and it is caused by a virus in the immune system. You can have subacute thyroiditis which is sudden and painful but it can heal on its own. Postpartum thyroiditis affects women after pregnancy but it is also short-lived. Silent thyroiditis is similar to postpartum but it doesn’t just affect women who have recently given birth and it is not painful.
  • Iodine induced thyroiditis occurs when you consume too much iodine, which is used by the body in order to produce the thyroid hormone.
  • Drug-induced thyroiditis occurs from taking too many medications that have the thyroid hormone in them. Those suffering from hypothyroidism and on thyroid replacement therapy are at risk for getting too much of the hormone.

Diagnosis

In many instances the physical symptoms of hyperthyroidism may be enough for an accurate diagnosis, especially if you already have one of the other diseases recognized to cause hyperthyroidism. In other instances there are other tests your physician can perform to get a correct diagnosis.

You may be given a physical exam so the doctor can see visual symptoms such as tremors, visual problems and a manual examination of the thyroid gland. Blood tests are also performed that can test thyroid hormone levels. There are several different lab tests to test hormone. One or both of these tests will confirm a hyperthyroidism diagnosis.

In some instances you may be required to undergo further tests to determine the cause of the overactive thyroid gland, particularly if you don’t suffer from one of the known causes of hyperthyroidism. You may be required to take a radioactive iodine test where you consume radioactive iodine to see how much was absorbed over a 24-hour period. Sometimes a simple thyroid scan will be conducted so your doctor can look at your thyroid gland through a camera on a screen.

Treatment

Currently several hyperthyroidism treatments exist, but the best treatment for you will depend on a variety of factors including your overall health, age, severity of your disease and the cause of your hyperthyroidism. Some treatments focus on the symptoms of the disease while others treat the cause of the overactive thyroid gland.

Therapies to Decrease Thyroid Hormone Levels:

Anti-thyroid Medications work to reduce the symptoms associated with hyperthyroidism. These medicines work by prohibiting the thyroid gland from producing more hormones than your body needs. Within 3 months these medications can start to improve your symptoms, sometimes permanently. Unfortunately these medications have some serious side effects including liver damage and death.

Radioactive Iodine is also used to treat hyperthyroidism. Taken orally the iodine gets absorbed by the thyroid gland and causes it to shrink. This shrinkage causes the symptoms to abate within about six months. In some instances radioactive iodine has been known to cause hypothyroidism.

Surgical Interventions are the recommended treatment for patients who are pregnant or unable to tolerate the anti-thyroid medications to treat this disease. If you can’t undergo radioactive iodine treatments then you may be a candidate for a thyroidectomy, which removes all or a portion of your thyroid gland.

Patients with Graves’ Disease may have the entire thyroid gland removed while those with Plummer’s Disease or an overactive nodule can have part of the thyroid gland removed, where the nodules are overactive.

Therapies to Decrease Hyperthyroid Symptoms are recommended to patients at the discretion of the doctor. Patients who are candidates for this type of therapy vary by a variety of factors. These beta adrenergic blocking agents, also known as beta blockers, block the release of the thyroid hormone into the body, which can reduce the heart rate and tremors. What’s more is that these agents do not change the levels of thyroid hormone in the blood.

If you think you may be a candidate for this symptom therapy, ask your treating physician about the following blocking agents:

  • Atenolol
  • Propanolol
  • Nadolol
  • Metoprolol
Hyperthyroidism As A Result Of Other Medical Treatments

Hyperthyroidism can occur as a result of other medical treatments for other health problems.

Amiodarone therapy is a drug to treat arrhythmia (abnormal heart rhythm). These tablets contain iodine and may contribute to an excessive release of the thyroid hormone. If you are currently undergoing amiodarone therapy you should get regular tests to gauge your baseline thyroid function.

CT scans are another method by which one can develop hyperthyroidism due to the amount of iodine found in the contrasting materials to make the organs visible. If you suffer from one of the causes of hyperthyroidism, you should get tested regularly to make sure your thyroid gland is working normally.

If you are at risk of hyperthyroidism you should inform your doctor so they can limit the treatments and procedures that expose you to iodine or other medicines that can affect your thyroid hormone production.

Prognosis

The general prognosis for those suffering from hyperthyroidism is positive. This disease can be easily treated and it is almost never fatal. Follow your treatment plan to the letter and follow up with your doctor regularly and you should have no complications with hyperthyroidism.

Untreated however, hyperthyroidism can present with many complications that can lead to serious health problems including death. Some of the symptoms may produce complications if left untreated, such as dehydration due to diarrhea, excess sweating and too much heat. An untreated arrhythmia can cause heart failure.

Some of the treatments of hyperthyroidism may also cause complications. Notably radioactive iodine therapy and hormone replacement therapy can cause hypothyroidism. Surgery to remove all or part of the thyroid gland present with its own set of complications most notably damage to the voice box and glands that regulate calcium. Damage to these glands can also lead to bone loss.

Avoid these complications by taking note of your symptoms and strictly abiding by the treatment plan created with your physician.

Written By Miranda Stephens

Miranda Stephens, MD is certified by the American Board of Family Medicine. Dr. Stephens earned her undergraduate degree from the University of Colorado.She completed a residency in Family Medicine at the University of Michigan at Ann Arbor. In 2006 Dr. Stephens was chosen for Alpha Omega Alpha Honor Medical Society.

Leave a Reply

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


*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>