Understanding More About Hypothyroidism

Hypothyroidism, also known as underactive thyroid, is a condition that results when your thyroid gland does not produce enough hormones.1,2 Those hormones include levothyroxine (T4 ) and liothyronine (T3), which help regulate your weight, energy level, mood, and other bodily functions.3,4 Hypothyroidism affects an estimated 10 million Americans and is 5-10 times more common in women than men.

Signs and Symptoms

When your thyroid hormones are unbalanced, symptoms related to thyroid conditions can occur. The most common symptoms of hypothyroidism are feeling tired (fatigue) and feeling cold.5

Common Symptoms of Hypothyroidism1,5,6

  • Hair

    Hair loss

  • brain fog

    Brain fog (forgetfulness)

  • difficulty

    Difficulty concentrating

  • slow speech

    Slow speech

  • dry skin icon

    Dry skin

  • constipation icon


  • irregular menstrual periods icon

    Heavy or irregular menstrual periods

  • weight gain icon

    Weight gain

Patient with indicators of their thyroid and pituitary gland

How Your Thyroid Works—Or Doesn’t Work

Your thyroid gland is a small butterfly-shaped organ located at the base of your neck. The thyroid creates hormones that control the speed of your metabolism, as well as how the body regulates body temperature and heart rate.7 T4 is the main type of thyroid hormone produced by the thyroid gland. However, T3 is the active form of thyroid hormone that impacts your cells.7 Most T3 is produced by the body converting T4 to T3.7

The pituitary gland, which is located in your brain, keeps checking the thyroid hormone levels in your body to make sure there isn’t too much—or too little.6

In hypothyroidism, either the thyroid gland or the pituitary gland is not working in a way to create the proper thyroid hormone balance for your body.5 10% to 15% of people still have hypothyroidism symptoms despite treatment with T4 alone.8 ADTHYZA® can supplement the T4 and T3 produced by the thyroid, and may be an option for patients still experiencing persistent symptoms.9