Hypothyroidism and Hashimoto’s disease

What is hypothyroidism?

Your thyroid is a small, butterfly-shaped gland at the front of your neck. It makes hormones that control how your body uses energy. They affect your heart rate, body temperature, digestion, and mood.

When your thyroid makes too little hormone, many body processes slow down. This is hypothyroidism, also called underactive thyroid.

Hashimoto’s disease is an autoimmune condition. Your immune system, which normally fights germs, attacks the thyroid by mistake. The damage usually happens slowly, over years. Not everyone with Hashimoto’s develops hypothyroidism.

What are the symptoms?

Symptoms often come on slowly, and early on there may be none. Many people learn they have hypothyroidism from a routine blood test. Symptoms can include:

• Feeling tired or sluggish
• Feeling cold when others don’t
• Constipation
• Dry skin and thinning hair
• Weight gain
• Muscle aches or stiffness
• Heavier or irregular periods
• Low mood, slow thinking, or trouble remembering things
• Swelling at the front of the neck (goiter)

What causes it, and who is at risk?

Hashimoto’s disease causes most cases of hypothyroidism in the United States. Other causes include:

• Surgery that removed part or all of the thyroid
• Radioactive iodine treatment for an overactive thyroid
• Radiation to the neck for cancer
• Some medicines, such as amiodarone and lithium
• Inflammation of the thyroid after pregnancy (postpartum thyroiditis)
• Problems with the pituitary gland, which is rare

You’re more likely to have Hashimoto’s if you’re a woman, have family members with thyroid disease, or have another autoimmune condition, such as type 1 diabetes, celiac disease, rheumatoid arthritis, or lupus. Women are about 8 times more likely than men to have Hashimoto’s.

How is hypothyroidism diagnosed?

Your clinician will ask about your symptoms, check your neck, and order blood tests:

• TSH (thyroid-stimulating hormone): a hormone made by the pituitary gland in your brain. It tells your thyroid to work harder. When thyroid hormone is low, TSH usually goes up.
• Free T4: the main hormone your thyroid makes. A low free T4 with a high TSH points to hypothyroidism.
• TPO antibodies: a positive result shows your immune system is attacking the thyroid, which points to Hashimoto’s.

Sometimes TSH is a little high while free T4 is normal. This is called subclinical hypothyroidism, and it may not need treatment. If your clinician feels a lump or an enlarged thyroid, you may also have a thyroid ultrasound, an imaging test that uses sound waves.

How is hypothyroidism treated?

The standard treatment is thyroid hormone replacement, a daily pill that gives your body the hormone your thyroid can’t make.

• Levothyroxine: a lab-made version of T4, the main thyroid hormone. It’s the most common thyroid medicine.
• Finding the right dose: your clinician checks your TSH about 6 to 8 weeks after a dose change and adjusts until it’s in your target range.
• Taking it the same way each day: usually on an empty stomach with water. Calcium, iron, and some other supplements can affect how well it’s absorbed, so they’re often taken a few hours apart.
• Watching mild cases: some people with subclinical hypothyroidism are watched with repeat blood tests instead of starting medicine.

Other thyroid hormone products exist, including ones that contain T3. Dr. Shah can go over what the research says about them and whether they make sense for you.

Living with hypothyroidism and when to get care

Once your dose is steady, you’ll usually have blood tests once or twice a year. Your dose may change with age, pregnancy, or new medicines. Request an appointment or call 646-389-0001 if:

• Your symptoms come back or don’t improve after your dose is set
• You’re planning a pregnancy or just found out you’re pregnant, since your dose often needs to go up early in pregnancy
• You start or stop a medicine or supplement that may affect your thyroid
• You notice a new lump or swelling in your neck

When to get emergency care

Severe, untreated hypothyroidism is rare but serious. Call 911 or go to the nearest emergency room if someone with hypothyroidism has extreme sleepiness or confusion, a very low body temperature, or slow or shallow breathing.

How Madison Medical Care helps

Sona Shah, MD, looks at your symptoms and thyroid blood tests together, explains what your numbers mean, and works with you on a dose and follow-up plan.

Dr. Shah is board-certified in Endocrinology, Diabetes & Metabolism by the American Board of Internal Medicine. She trained at Weill Cornell and St. Luke’s Roosevelt and has a decade of experience in adult endocrinology, with a particular interest in women’s health and in pairing lifestyle changes with evidence-based medicine.

• Visits are in person at 30 E 23rd St, Floor 7, near Madison Square Park.
• Your first visit is 30 minutes. Follow-up visits are 15 minutes.
• Request an appointment online or call 646-389-0001. Our Patient Support Team will contact you within 2 business days.
• We’re a self-pay practice and don’t bill insurance for visits. Your labs, imaging, and prescriptions still go through your insurance.
• We can’t see patients who have Medicare or Medicaid.