The symptoms of thyroid disease — including difficulty sleeping, unintentional weight loss, fatigue, anxiety, irregular heartbeat — could apply to a variety of conditions.

But if you’ve experienced these symptoms and struggle to pin it on a cause, your physician may want to check how your thyroid is functioning.

Your thyroid gland, located in your neck, controls every aspect of your body’s metabolism, including regulating the level of thyroid hormones that flow into your bloodstream.

“In hypothyroidism, your thyroid gland is underactive, meaning it can’t make enough hormones. Low levels or lack of such an essential hormone will affect other body functions and cause symptoms,” said Mahmoud Alsayed, MD, a specialist in endocrinology, diabetes and metabolism with Endeavor Health.

On the other hand, with hyperthyroidism your thyroid gland is overactive and produces too much of the thyroid hormones,” he said. “Hyperthyroidism can manifest as nonspecific symptoms, such as anxiety, weight loss or your heart racing, which might delay the diagnosis.

Hypothyroidism

Hypothyroidism slows your metabolism and can cause symptoms such as:

  • Tiredness
  • Weight gain
  • Constipation
  • Increased sensitivity to cold
  • Dry skin or dry, thinning hair
  • Depression
  • Joint and muscle pain
  • Slowed heart rate
  • Heavy or irregular menstrual periods
  • Slower increase in height in children

Sometimes your thyroid gland becomes bigger than normal (called goiter) and causes the front of your neck to look swollen.

Hypothyroidism often develops slowly over many years. The most common cause of hypothyroidism is Hashimoto’s disease, an autoimmune disorder in which the immune system attacks the thyroid so that it can’t make enough thyroid hormones. Untreated, hypothyroidism can lead to health issues like high cholesterol, high blood pressure and heart problems.

"Fortunately, hypothyroidism can often be completely controlled with a hormone medicine called levothyroxine, or Synthroid, which you take once a day on empty stomach. It is important to take it by itself, not with food or other medications.” Dr. Alsayed said. “Your doctor will likely order routine blood tests to monitor and adjust the doses if needed."

Hyperthyroidism

Hyperthyroidism accelerates your body’s metabolism and can cause one or more of these symptoms:

  • Increased appetite yet unintentional weight loss
  • Nervousness, irritability
  • Fatigue, tiredness, muscle weakness
  • Increased sensitivity to heat
  • Rapid or irregular heartbeat
  • Shaky hands
  • Difficulty sleeping
  • Frequent bowel movements or diarrhea
  • Increased appetite

In people over age 60, hyperthyroidism may cause other symptoms, such as loss of appetite or withdrawal from people.

The most common cause of hyperthyroidism is Graves’ disease. Graves’ disease is an immune system disorder that most commonly affects women under age 40. This condition can also lead to Graves’ ophthalmology, which affects tissues and muscles behind the eyes.

There are a variety of options to treat hyperthyroidism, including antithyroid medications, radioactive iodine ablation and thyroid surgery,” Dr. Alsayed said. “If it’s not treated, hyperthyroidism can lead to serious problems with the heart, bones, muscles, menstrual cycle and fertility.

Even though thyroid disorders are very common, thyroid cancer is extremely rare. Unlike hypothyroidism or hyperthyroidism, thyroid cancer typically has few warning signs.

It is important for you to listen to your body and look out for any signs and symptoms of thyroid cancer:

  • A lump in the neck, sometimes growing quickly
  • Swelling in the neck
  • Pain in the front of the neck, sometimes going up to the ears
  • Hoarseness or other voice changes that do not go away
  • Trouble swallowing or trouble breathing
  • A constant cough that is not due to a cold

If you feel like something could be wrong with your thyroid gland, talk to your doctor. Thyroid conditions can be successfully managed by taking medicine as prescribed, getting regular checkups and following a healthy lifestyle.