Symptoms of hypothyroidism begin slowly over weeks or months. You may have hypothyroidism for a long time before you realize you are ill. Symptoms change with the degree of hypothyroidism and how long your body has not had the proper amount of thyroid hormone.

You may have only one of these symptoms, but most people have a combination. Some with hypothyroidism do not have symptoms or have mild symptoms that go unnoticed for a long period of time.  

Symptoms include:

• Enlarged thyroid gland, called goiter (not always present)
• Fullness in the neck
• Difficulty swallowing or trouble breathing (can happen if the goiter is very large)

Goiter Copyright © Nucleus Medical Media, Inc.

Other symptoms or signs include:

• Fatigue
• Weakness
• Coarse, brittle hair and hair loss
• Dry, scaly skin
• Unable to tolerate cold temperatures
• Weight gain (may happen despite having a poor appetite)
• Constipation
• Achy feeling all over
• Depression and irritability
• Memory loss and personality changes
• Irregular or heavy menstrual periods
• Facial puffiness
• Swollen feet or hands
• Infertility
• Reduced sweating

Symptoms of severe or extended cases include:

• Swelling of the skin and tissue around the eyes
• Bradycardia—slow heart rate
• Hypothermia—low body temperature
• Shortness of breath during activity or when lying flat
• Drowsiness and lower mental alertness