If you have ever complained to your doctor about fatigue, irregular periods, and weight gain, there is a good chance that you were tested for hypothyroidism. Hypothyroidism, an endocrine disorder where your thyroid doesn’t create enough hormones, is fairly common — an estimated 4-10% of women have it! 

However, what if your test results come back and your thyroid hormone levels aren’t low enough to be diagnosed with hypothyroidism, but you are still experiencing symptoms of hypothyroidism? You might have what experts call subclinical hypothyroidism. 

nurse prepping a patient for a blood draw

What is subclinical hypothyroidism? 

Your thyroid — a butterfly-shaped gland in your neck — plays an important role in several of your body’s processes, including regulating your weight and metabolism, menstrual cycle, and cholesterol levels. If your thyroid doesn’t produce enough of these hormones, you might experience symptoms like weight gain, fatigue, constipation, dry skin, and more. 

Subclinical hypothyroidism is a milder form of hypothyroidism, and what many doctors consider “pre-hypothyroidism.” An estimated 3-8% of people have subclinical hypothyroidism, even though their thyroid hormone levels are considered “normal.” Many people with subclinical hypothyroidism experience symptoms similar to hypothyroidism, and some don’t experience any symptoms at all.

25% of people with subclinical hypothyroidism will eventually develop hypothyroidism, which is why many doctors recommend early treatment and detection. “Early treatment can prevent symptoms from worsening over time,” says Dr. Cordelia Nwankwo, MD, FACOG. “Fortunately, early treatment can normalize thyroid hormone levels and reverse symptoms, and many people with subclinical hypothyroidism see their hormone levels normalize without any intervention.”

doctor examining a women's thyroid

What are the symptoms of subclinical hypothyroidism?

The symptoms of subclinical hypothyroidism are similar to the symptoms of hypothyroidism, which include:

  • Unexplained weight gain

  • Constipation

  • Feeling cold

  • Fatigue

  • Puffy face and dry skin and hair

  • Irregular periods

You don’t have to suffer from these symptoms if they are getting in the way of your life! With early intervention and treatment, it's very possible to treat subclinical hypothyroidism so it doesn’t further develop into hypothyroidism. Many people report feeling better within a few weeks of treatment.

Who is at risk for developing subclinical hypothyroidism? 

There is no single risk factor or cause of subclinical hypothyroidism, but several things can increase the likelihood of developing it:

  • Gender: Women are more likely to develop hypothyroidism, for reasons that aren’t entirely known yet. According to Dr. Nwankwo, women are more likely to develop hypothyroidism because thyroid disorders are related to autoimmune reactions, which are more common in women than men. Thyroid hormones also play a role in the menstrual cycle, which is why it tends to impact more women.

  • Pregnancy: For reasons not entirely unknown, some women experience hypothyroidism after pregnancy, likely due to the autoimmune reaction. According to the American Thyroid Association, 5-10% of women develop postpartum hypothyroidism, and most women see their normal thyroid hormone levels normalize within 18 months of developing symptoms.

  • Hashimoto’s thyroiditis: You’ve probably heard about Hashimoto’s thyroiditis, a disease that causes your body to create anti-thyroid antibodies to use against your thyroid. It’s also one of the leading causes of subclinical hypothyroidism. If you have been diagnosed with Hashimoto’s, you are not alone — many celebrities, like Gigi Hadid, Oprah, and Sofia Vergara have opened up about their treatment journeys with the autoimmune condition!

  • Medication: Some medications, including lithium, a treatment for bipolar disorder, certain heart and cancer medications, and medications designed to treat hyperthyroidism (aka an overactive thyroid) can also cause subclinical hypothyroidism. If you are on these medications, your doctor should talk to you about options to test and potentially treat subclinical hypothyroidism.

woman taking a pill

What are the treatment options?

Fortunately, subclinical hypothyroidism can be diagnosed and treated quickly. According to Dr. Nwankwo, the best treatment option for subclinical hypothyroidism is hormone replacement. The most common medication, Levothyroxine, replaces the hormone your thyroid isn’t making enough of.

After you have been diagnosed, your doctor will likely ask for you to return for follow-up bloodwork within 6 to 8 weeks to see how your body is reacting to treatment and might adjust your dosage until your thyroid hormone levels return to normal. Before you stop your medication — even if your thyroid levels are normal — it’s important to talk to your doctor to come up with the best plan for you.

Subclinical hypothyroidism doesn’t have to slow down your life. If any of the symptoms sound familiar to you, talk to your doctor about testing and treatment, so you can get back to feeling your best.

Erin Pettis is a content strategist, freelance writer, and women’s health advocate. She lives in New York City and holds an MBA from NYU’s Stern School of Business.