Symptoms Of Hyperthyroidism: What Is The Thyroid? and Possible Complications

The thyroid is a small butterfly-shaped gland in the neck that helps regulate how quickly or slowly the body uses energy.

In other words, it is key to a person’s metabolism.

Hyperthyroidism is a condition in which an overactive thyroid gland produces an excessive amount of thyroid hormones that circulate in the blood (“Hyper” means “on” in Greek).

Thyroid hormones include thyroxine (T4) and triiodothyronine (T3), representing 99.9% and 0.1% of thyroid hormones. T3 is the most active thyroid hormone. Much of the T4 becomes T3 in the bloodstream.

Symptoms of hyperthyroidism

When you have hyperthyroidism, your body produces excessive amounts of the thyroid hormones T3 and T4. Since these hormones regulate your metabolism (how your body processes and uses energy), having too high a level will cause symptoms related to a high metabolism.

In essence, hyperthyroidism accelerates some of the processes in your body.

However, not all people with hyperthyroidism will experience all the symptoms listed below.


These are all possible symptoms, but the symptoms vary depending on how long your thyroid gland has produced too much T3 and T4, the additional T3 and T4 you have, and your age.

This is what you may experience with hyperthyroidism:

  • Change of appetite (decrease or increase).
  • Difficulty sleeping ( insomnia ).
  • Fatigue.
  • Frequent stools, maybe diarrhea.
  • Palpitations of the heart ( tachycardia ).
  • Heat intolerance.
  • Increased sweating
  • Irritability.
  • Light menstrual periods, perhaps even lost periods.
  • Mental disturbances
  • Muscular weakness.
  • Nervousness.
  • Problems with fertility.
  • Changes in the menstrual cycle.
  • Short of breath.
  • Sudden paralysis
  • Tremors
  • Changes in vision
  • Loss or increase of weight.
  • Dizziness.
  • Thinning hair
  • Itching and hives.
  • Possible increase in blood sugar.

They are less likely to appear if you are an older adult, but sometimes there will be subtle symptoms. These may include a faster heart rate or being more sensitive to high temperatures. Alternatively, you may feel more tired than usual from everyday activities.

Graves disease:

If Graves’ disease is the underlying cause of your hyperthyroidism, some additional symptoms are associated with that.

The most common cause of hyperthyroidism is an immune system disorder called Graves’ disease. It is more likely to affect women under 40 years of age.

In addition to the other symptoms of hyperthyroidism, about 30% of people with Graves ‘disease develop a condition called Graves’ ophthalmopathy. It affects the eyes and vision, including the muscles and tissues surrounding them.

You can experience:

  • Bulge of your eyes (exophthalmos).
  • A gritty feeling or pain.
  • Pressure in your eyes.
  • Redness or swelling in or around your eyes.
  • Swelling or retraction of your eyelids.
  • Sensitivity to light.
  • Double vision.
  • Loss of vision

Sometimes people with Graves ‘disease also develop a symptom called Graves’ dermopathy, but this is rarer. It involves redness and thickening of the skin, usually on the upper part of the feet or shins.

What are some of the possible complications of hyperthyroidism?

Eye problems:

Graves ‘ophthalmopathy is an eye condition associated with Graves’ disease. It can cause red and swollen eyes and sensitivity to light, and double vision.

Heart problems:

A rapid heart rate, irregular heartbeat, and congestive heart failure are potentially severe complications of hyperthyroidism. Fortunately, these complications can be avoided with quick and adequate treatment.


Hyperthyroidism can cause thinning or fragility of bones or osteoporosis. This is because the excess thyroid hormone prevents the body from using calcium, a mineral that strengthens the bones.

Skin problems:

Graves’ dermopathy is a rare condition where the skin, often on the legs and feet, becomes red and swollen.

Thyrotoxic crisis:

You also called thyroid storm. It is a sudden onset of rapid heart rate and fever symptoms. If you think your child is experiencing a thyrotoxic crisis, you should seek immediate medical attention.