Dr. Ronald Goldenberg, MD, Clinical and Research Endocrinologist
Hypothyroidism, or an underactive thyroid, occurs when the butterfly-shaped thyroid gland in the neck does not produce enough thyroid hormones to properly regulate the body’s metabolism. This slowing of metabolic activity can affect nearly every organ system, leading to symptoms such as fatigue, weight gain, cold intolerance, dry skin, and constipation.
Dr. Ronald Goldenberg, MD, Clinical and Research Endocrinologist
Symptoms
Symptoms often develop gradually and may initially resemble normal aging or stress. Common symptoms include:
- Persistent fatigue and weakness
- Unexplained weight gain or difficulty losing weight
- Feeling unusually cold
- Dry, coarse skin and brittle hair
- Constipation
- Muscle aches, stiffness, or joint pain
- Brain fog or memory difficulties
- Low mood or depression
Dr. Ronald Goldenberg, MD, Clinical and Research Endocrinologist
Causes
The most common cause in developed countries is Hashimoto’s disease, an autoimmune condition in which the immune system attacks the thyroid gland.
Other causes include:
- Thyroid surgery
- Radiation therapy involving the neck
- Certain medications, including Lithium and Amiodarone
- Pituitary gland disorders
- Iodine deficiency (rare in North America but common worldwide)
Dr. Ronald Goldenberg, MD, Clinical and Research Endocrinologist
Diagnosis
Because symptoms are nonspecific, diagnosis requires blood testing. Doctors usually measure:
- TSH (Thyroid-Stimulating Hormone)
- T4 (Thyroxine)
An elevated TSH with a low T4 level typically indicates hypothyroidism.
Dr. Ronald Goldenberg, MD,
Dr. Ronald Goldenberg, MD,
Dr. Ronald Goldenberg, MD,
Registered Dietician Andy Desantis
Treatment
Treatment is generally effective and involves replacing the missing thyroid hormone with daily synthetic hormone therapy, most commonly Levothyroxine.
Key points about treatment:
- Most people require lifelong medication
- Regular blood tests help ensure the dose remains appropriate
- Symptoms often improve gradually over weeks to months
Without treatment, hypothyroidism can contribute to elevated cholesterol, cardiovascular disease, infertility, nerve damage, and other complications.