What Are the Side Effects of High Thyroid Levels?

Hyperthyroidism or overactive thyroid occurs when your thyroid gland produces too much of the hormone thyroxine. Since this hormone controls the body's metabolism rate, hyperthyroidism can affect every organ in the body. Symptoms occur both when your thyroid is overproducing the hormone or when you take too much thyroxine in tablet form.

Weight

Weight loss is common with hyperthyroidism, even if you are eating more than usual. Appetite may be decreased.

Heart

Hyperthyroidism can cause a rapid heart rate (often more than 100 beats a minute), palpitations (a feeling of pounding in the chest) and irregular heart beat. It also can cause feelings of anxiety, irritability and nervousness.

Temperature

Increased perspiration and sensitivity to heat are indications of too much thyroid hormone.

Eyes

Graves' disease, the most common form of hyperthyroidism, can cause protruding eyeballs, discomfort and redness of the eyes, or sensitivity to light.

Neck Swelling

A swelling at the base of your neck may indicate an enlarged thyroid.

Other Symptoms

A lighter menstrual flow, more frequent bowel movements, tremor in the hands or fingers, muscular weakness, thinning skin and fine, brittle hair are all symptoms of excess thyroid hormone. A hyperthyroid patient may feel fatigued, yet have trouble sleeping.

References

• Mayo Clinic: Hyperthyroidism
• American Thyroid Association: Hyperthyroidism