Hypothyroidism: An Underactive Thyroid

When the thyroid doesn’t work hard enough, it’s called hypothyroidism. If you have hypothyroidism, your body runs more slowly and you have less energy. Your thyroid gland doesn’t produce enough hormone.

The thyroid hormone (THS) is the thyroid’s messenger. Your thyroid gland makes thyroid hormone from iodine, which is absorbed from the food you eat. When less thyroid hormone is produced, the cells work slower.

The most common cause of hypothyroidism is Hashimoto thyroiditis. In people with this condition, the body’s immune system (the system that helps your body fight infection) mistakes the thyroid gland for something it needs to attack. Hypothyroidism may also occur if there’s not enough iodine available for the thyroid to make hormone, if there are problems with the pituitary gland, or if the thyroid gland is removed.

You may notice one or more of these symptoms:

• Decreased energy level, fatigue
• Feeling cold
• Muscle pain
• Slowed thinking
• Constipation
• Longer and heavier menstrual periods
• Weight gain
• Dry and brittle skin, hair and nails
• Feeling down or depressed

Common causes of hypothyroidism include:

• Hashimoto’s thyroiditis
• Non specific thyroiditis
• Previous thyroid surgery
• Radiation therapy for Head and Neck Cancer

Read about thyroid treatment.