Untreated hypothyroidism can cause persistent symptoms like fatigue, dry skin, constipation, and weight gain. It can also lead to potentially serious complications.

Hypothyroidism is a condition where the thyroid gland makes too little thyroid hormone. It’s treated by taking medication that replaces the missing thyroid hormone.

While hypothyroidism can be effectively managed, researchers found that between 2009 and 2019, an estimated 14.4% of people in the United States with a hypothyroidism diagnosis weren’t receiving treatment.

Untreated hypothyroidism can lead to potentially serious complications.

This article looks at what exactly happens if you don’t treat hypothyroidism.

Thyroid hormone is important for a variety of processes in your body, especially managing your metabolism, which is how your body uses energy. It’s also involved in things like heart rate, brain health, and fertility (just to name a few).

In hypothyroidism, your thyroid gland isn’t making enough thyroid hormone to properly maintain these processes. This means that many of the processes start to slow down.

As such, untreated hypothyroidism can have several immediate symptoms. These include:

The exact symptoms of untreated hypothyroidism can vary from person to person. However, if you’re regularly experiencing any of the symptoms on this list, it’s a good idea to make an appointment with a doctor or medical professional to discuss.

If hypothyroidism remains untreated, it can lead to several potentially serious complications. Some research has also suggested that untreated hypothyroidism is associated with an increased risk of death from any cause.

The following sections review the potential complications of untreated hypothyroidism.

High cholesterol and heart disease

Thyroid hormones are involved in the metabolism of lipids (fats) in your body. Because of this, thyroid dysfunction can alter lipid levels.

Hypothyroidism is associated with dyslipidemia, a condition where levels of one or more types of lipid are higher than normal. Specifically, hypothyroidism can increase total cholesterol, LDL (“bad”) cholesterol, and triglycerides.

High cholesterol can boost the risk of heart disease. Further, hypothyroidism can weaken the ability of the heart to pump and slow the heart rate, which can also raise your risk of heart disease.

Research has found that treatment for hypothyroidism can improve lipid levels and help to potentially reverse the effects of low thyroid hormone on the heart and blood vessels, lowering the risk of heart problems.

Infertility and pregnancy complications

Hypothyroidism is known to be linked to infertility. This is mostly due to disturbances in ovulation.

Ovulation is when an egg is released from the ovaries and becomes available to be fertilized. Problems with ovulation are one of the most common causes of infertility.

Having hypothyroidism during pregnancy can also lead to complications like:

Managing hypothyroidism can help prevent infertility and pregnancy complications.

Developmental issues in children

Congenital hypothyroidism is when low thyroid hormone is present from birth. It’s estimated to affect 1 in 3,000 to 4,000 infants.

In the United States and many other countries, newborns are tested for this condition right after birth.

If left untreated, hypothyroidism in infants can lead to intellectual disabilities. However, neonatal screening followed by prompt treatment has been shown to help improve developmental outcomes.

Myxedema coma

Myxedema coma is a serious complication that’s caused by severe untreated hypothyroidism.

When thyroid hormone levels get very low, the body’s processes can slow down in a dangerous way.

While myxedema coma is rare, it’s a medical emergency that requires immediate attention. Treatment involves giving replacement thyroid hormones as well as supportive care.

Hypothyroidism is treated using a medication called levothyroxine. This medication is a lab-made version of the thyroid hormone your body makes naturally. As such, levothyroxine helps to replace missing thyroid hormone.

You take levothyroxine once each day, typically in the morning prior to eating. It’s often taken in the form of a pill, but is also available as a gel capsule or as a liquid.

After you’ve been taking levothyroxine for a few weeks, your doctor will test your levels of thyroid hormone. This is to see if your levothyroxine dose has restored your thyroid hormone levels to a healthy range.

If the test results show that thyroid hormone levels are too low or too high, your doctor will adjust your daily dose of levothyroxine. They’ll then repeat the test in a few weeks.

Be sure to talk with your doctor if you continue to have symptoms or if you have any additional questions about your thyroid or your thyroid medication.

Some people with hypothyroidism remain untreated. Untreated hypothyroidism can lead to the persistence of symptoms like fatigue, weight gain, constipation, and dry skin.

Over time, untreated hypothyroidism can also cause potentially serious complications. These include high cholesterol, infertility, pregnancy complications, and the life threatening condition myxedema coma.

Hypothyroidism can be treated with levothyroxine. If you’ve noticed that you have symptoms consistent with hypothyroidism, make an appointment with a doctor to discuss them.