Subclinical Hyperthyroidism

What is subclinical hyperthyroidism?

Subclinical hyperthyroidism is a condition that develops when the amount of thyroid stimulating hormone (TSH) in your blood is low. TSH is made in the brain and controls how much thyroid hormones are made. You may experience symptoms even though your thyroid hormone levels are normal. Thyroid hormones help control body temperature, heart rate, growth, and how you gain or lose weight.

What causes or increases my risk of having subclinical hyperthyroidism?

• Autoimmune diseases: A problem with the immune system may make your thyroid gland produce too much thyroid hormone. Grave's disease is an example of an autoimmune disease that increases thyroid hormone.
  
  
• Family history: Your risk is greater if a family member has thyroid disease or an autoimmune disease
  
  
• Medicines: Certain medicines can cause hyperthyroidism. Ask your caregiver if any of the medications you are taking can cause hyperthyroidism.
  
  
• Diseases: A disease that affect certain parts of the brain can cause subclinical hyperthyroidism.

What are the signs and symptoms of subclinical hyperthyroidism?

You may have no signs and symptoms, or you may have general signs and symptoms of hyperthyroidism:

• Weight loss without trying, and increased appetite
  
  
• Fast heart rate and fast breathing, even at rest
  
  
• Bulging eyes
  
  
• Increased sweating, and heat intolerance
  
  
• Painful lump in your neck
  
  
• Fatigue, and difficulty sleeping
  
  
• Tremors and muscle weakness
  
  
• Decreased or absent monthly periods
  
  
• Diarrhea or constipation
  
  
• Nervous, tense, and restless

How is subclinical hyperthyroidism diagnosed?

Your caregiver will ask about your symptoms and examine you. He will ask what medicines you take. He will ask about your medical history and if anyone in your family has thyroid disease. You will have blood tests to check your TSH and thyroid hormone level.

How is subclinical hyperthyroidism treated?

You may not need any treatment, or you may need any of the following:

• Antithyroid medicines: These medicines decrease thyroid hormone levels. They may also decrease and prevent the signs and symptoms of hyperthyroidism.
  
  
• Radioactive iodine: A radioactive form of iodine is given to damage or kill some thyroid gland cells. This may decrease the amount of thyroid hormones made by the thyroid gland. If you are a woman, tell your caregiver if you know or think you might be pregnant. This medicine can be harmful to an unborn baby.
  
  
• Surgery: You may need surgery to remove all or part of your thyroid gland. By making the thyroid gland smaller, the amount of thyroid hormones produced will decrease.

What are the risks of subclinical hyperthyroidism?

• Treatment that is too early or uses too much medicine to decrease your thyroid hormone levels may cause problems. Medicines may cause your skin to itch and turn yellow or your joints to hurt. The medicines can also harm your liver. Medicines or surgery may damage thyroid gland cells and cause hypothyroidism (too little thyroid hormone). During surgery, you may bleed or get an infection.
  
  
• Untreated subclinical hyperthyroidism can worsen and turn into hyperthyroidism. You may lose weight, have a hard time falling asleep, and feel nervous and restless. You may also feel warm when other people feel cold, and have shortness of breath and a very fast heartbeat. You may also develop heart disease, low bone density, and other medical problems. Your risk of an abnormal heartbeat is also increased. If you are pregnant, subclinical hyperthyroidism may cause problems for you and your baby.

When should I contact my caregiver?

Contact your caregiver if:

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

When should I seek immediate help?

Seek help immediately or call 911 if:

• You have sudden chest pain or trouble breathing.
  
  
• You faint or have a seizure.
  
  
• Your heart is beating very fast or slow, and you are restless.
  
  
• Your signs and symptoms return or become worse.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

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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.

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