What are the symptoms of hypothyroidism in women?

What does an underactive thyroid do?

Your thyroid is a small, butterfly-shaped gland in the front of your neck. Its hormones control how your body uses energy, so they affect almost every organ, even how fast your heart beats.

When the thyroid makes too little hormone, many body functions slow down. That's why the symptoms can seem so wide-ranging.

What are the most common hypothyroidism symptoms?

Symptoms vary from person to person and may be mild. Common ones include:

• Feeling very tired, even after sleep.
• Feeling cold more than other people.
• Weight gain.
• Constipation.
• Dry skin, and dry or thinning hair, or hair loss.
• Joint and muscle aches.
• Low mood or depression.
• Trouble concentrating or thinking clearly.
• A hoarse, croaky voice.
• A slower heart rate.
• Heavy or irregular periods.

Why are women more likely to get hypothyroidism?

The most common cause is Hashimoto's disease, an autoimmune condition where your immune system attacks your thyroid by mistake. It's more common in women and often starts between ages 30 and 50.

You're also more likely to have an underactive thyroid if a close relative has thyroid disease, you've had thyroid surgery or radiation, you have type 1 diabetes or another autoimmune condition, or you were pregnant in the last 6 months. Hypothyroidism is also more common after age 60.

How does the thyroid affect your periods?

Thyroid hormones help control your cycle, so an underactive thyroid can make periods heavier, more irregular or further apart. It can also affect ovulation, which can make it harder to get pregnant.

That's why doctors often check thyroid levels when someone has cycle changes or trouble getting pregnant. Hypothyroidism during pregnancy can affect both parent and baby, but treatment helps prevent problems.

What does a TSH test show?

TSH, or thyroid-stimulating hormone, comes from the pituitary gland in your brain. It tells your thyroid how hard to work.

When thyroid hormone is low, the pituitary makes more TSH to push the thyroid harder. So a high TSH is often a sign of an underactive thyroid, and a low TSH can be a sign of an overactive one.

If your TSH is outside your lab's reference range, your doctor will usually order more tests, such as T4 (thyroxine) and thyroid antibodies. Pregnancy, some serious illnesses and older age can also shift TSH, so results are read alongside your symptoms and history.

How is hypothyroidism treated?

It's usually treated with a daily tablet that replaces the hormone your thyroid can't make, most often levothyroxine. Many people take it for life.

Your doctor usually rechecks your blood about 6 to 8 weeks after you start or change a dose, then once you're settled, about every 6 to 12 months. Never stop or change your thyroid medicine without talking to your doctor first.

If you take thyroid medicine and find out you're pregnant, contact your doctor right away, because the dose often needs checking during pregnancy.

Could it be something else?

Tiredness, weight gain and low mood are common and have many causes, including anemia, depression, perimenopause and poor sleep. That's why hypothyroidism can't be diagnosed from symptoms alone, and a blood test matters. Only a doctor can diagnose this.