Feeling tired? Having issues with weight gain? Hair loss? Anxiety? Your thyroid might be to blame. Our thyroids affect almost every one of our bodily functions. But don’t worry! Hypothyroidism is easy to correct in most people.
The hard part is putting the signs together and recognizing the issue. Without treatment, an underactive thyroid can cause serious mental and physical health problems.
What is the thyroid, and what does it do?
The thyroid is a small, butterfly-shaped gland in the front of your neck. It is a thyroid hormone factory! Thyroid hormones control everything — your body temperature, heart rate, blood pressure, metabolism, weight. They even affect how your skin, hair, and nails behave.
Your thyroid gland takes iodine from your blood to make the hormone thyroxine or T4. The “4” is because it has four iodine molecules. Another thyroid hormone is T3 — with three iodine molecules. More on the iodine later.
Your thyroid is in constant communication with your brain. Your brain sends out a signal called thyroid stimulating hormone (TSH). TSH tells the thyroid when the factory needs to up its production. When the body has enough thyroid hormone, the brain relaxes. It sends out less TSH telling the thyroid to make less hormones. How’s that for teamwork?
What is hypothyroidism, and what causes it?
Hypothyroidism is when the thyroid does not make enough thyroid hormone to meet the body’s needs. It affects about 4.6% of the population, or almost 5 out of every 100 people (mostly women). People over the age of 60 are at especially high risk. Other important risk factors include:
- Medications: Certain medications can affect your thyroid hormone levels. Some common ones are:
- Thyroid surgery: If you had part of your thyroid removed, what’s left might not be able to make enough hormones for your body.
- History of hyperthyroidism: Previous treatment for too much thyroid hormone can leave you without enough. Also, an overactive thyroid can burn itself out and then be unable to keep up.
- Radiation to the area: Radiation for treatment of head and neck cancers can hurt the thyroid gland as a side effect. The same radiation beams that kill the cancer cells can also damage the body’s normal tissues.
- Family history: You have a higher chance of having hypothyroidism if your family members have it — specifically close family members like parents, grandparents, or siblings.
- Pregnancy in the past 6 months: Autoimmune thyroid issues (called Hashimoto’s thyroiditis) can flare up after pregnancy. An autoimmune disease is when your immune system attacks your body. In this case, your immune system attacks your thyroid gland.
- Having an autoimmune condition: Having one autoimmune disease increases your chances of getting others, such as Hashimoto’s thyroiditis. These include type 1 diabetes, rheumatoid arthritis, celiac disease, alopecia areata (sudden hair loss), vitiligo (a disease that causes loss of skin color), and pernicious anemia (decrease in red blood cells).
- Iodine deficiency: Without iodine, the thyroid gland can’t make thyroid hormone. This is now mostly an issue in developing countries and not in the U.S. In the U.S., iodine is added to salt and other foods to prevent deficiency.
What are some common signs of hypothyroidism?
This is the tricky part. It’s easy to attribute the signs of hypothyroidism to something else. Stress, aging, not enough sleep, not drinking enough water. Typically, the effects creep up on you over months to years. Here’s what to look out for:
- Low energy level, even when you get enough sleep
- Weight gain, even when you are not overeating
- Skin, hair, and nail changes (dry skin, hair loss, and brittle nails)
- Irregular periods
- Feeling cold when others don’t
- Pins and needles feeling (a tingling or prickling sensation in your hands, arms, legs, or feet)
- Swelling and puffiness
- Decreased libido
Listen to your body. Report your symptoms to your primary care doctor. They will take your history, examine you, and decide if you need testing.
How do you detect hypothyroidism?
Hypothyroidism is diagnosed with a blood test. Most commonly, your provider will check your level of thyroid stimulating hormone (TSH) as a screening tool. A high TSH level means there is not enough thyroid hormone in your blood. The brain is sending signals to the thyroid to make more. Depending on the results, your doctor might order another blood test to check a full thyroid panel or test for autoimmunity.
In most labs, the normal range for TSH is 0.4 mU/L to 4.0 mU/L. A TSH higher than 4.0 mU/L could mean hypothyroidism. Lower than 0.4 mU/L points to hyperthyroidism. In pregnancy, the range is lower. With older age, the range is higher.