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Subclinical Hypothyroidism


  • Subclinical hypothyroidism is a condition where the level of the thyroid stimulating hormone (TSH) in your blood is slightly higher than normal. TSH is produced by the brain in the hypothalamus and the pituitary gland. TSH controls how the thyroid gland works by telling it how much thyroid hormones to make. The thyroid hormones help keep your body working normally. The two forms of thyroid hormones in the blood are T3 and T4. When these hormones become low, the brain releases more TSH to tell the thyroid to make more hormones. If the thyroid hormone levels are too high, the brain slows down making TSH. With subclinical hypothyroidism, the TSH is slightly higher than normal while the thyroid hormone levels are normal.
    Thyroid and Parathyroid Glands

  • Subclinical hypothyroidism may be caused by problems with the immune system, certain medicines, treatments, and other diseases. You may have no signs and symptoms, or you may have general signs and symptoms of hypothyroidism. Blood tests, thyroid scan, or thyroid ultrasound may be used to learn if you have this condition. Treatment depends on your health, age, and the levels of your TSH and thyroid hormones. Treatment may include thyroid medicine, or other medicine to decrease your symptoms or treat the cause of your hypothyroidism. Learning that you have subclinical hypothyroidism and beginning treatment if needed can prevent it from worsening and help you feel better.


Take your medicine as directed:

Call your primary healthcare provider if you think your medicine is not working as expected. Tell him if you are allergic to any medicine. Keep a current list of the medicines, vitamins, and herbs you take. Include the amounts, and when, how, and why you take them. Take the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency. Throw away old medicine lists.

Follow-up visit:

  • Keep all appointments. Write down any questions you may have. This way you will remember to ask these questions during your next visit. You may need to have a repeat blood test 2 to 12 weeks after your first TSH test. Depending on the results and treatments given, your caregiver will tell you when your blood needs to be checked.

  • TSH and thyroid hormone levels will be checked at least every 6 to 12 months for several years. This is done when TSH levels become normal and there are no signs and symptoms of hypothyroidism. Ask your caregiver when to come back and how often you need your blood tested.

Diet and nutrition:

With low thyroid hormone levels, you may need to eat foods that are high in iodine. Iodine is an important mineral used by the thyroid gland to work correctly and make thyroid hormones. These foods include table salt, milk, fish, clams, and other seafood. Ask your caregiver which foods are best for you, and if you need to follow a special diet.


  • You have a fever.

  • You have pain, redness, and swelling in your muscles and joints.

  • You cannot make it to your next caregiver visit.

  • You have questions or concerns about your condition or medicines.


  • You have chest pain or trouble breathing all of a sudden.

  • You have swelling in your legs, ankles, or feet.

  • You just fainted or had a seizure (convulsion).

  • Your heart is beating very fast or slow, or you are becoming very restless.

  • Your signs and symptoms return or become worse.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Learn more about Subclinical Hypothyroidism (Aftercare Instructions)