Hypothyroidism occurs when your body doesn’t produce enough thyroid hormones. The thyroid is a small, butterfly-shaped gland that sits at the front of your neck. It releases hormones to help your body regulate and use energy.

Your thyroid is responsible for providing energy to nearly every organ in your body. It controls functions such as how your heart beats and how your digestive system works. Without the right amount of thyroid hormones, your body’s natural functions begin to slow down.

Also called underactive thyroid, hypothyroidism affects women more frequently than men. It commonly affects people over the age of 60 years old, but it can begin at any age. It may be discovered through a routine blood test or after symptoms begin.

Subclinical hypothyroidism is the name given to an early, mild form of the condition.

If you’ve recently been diagnosed with hypothyroidism, it’s important to know that treatment is considered simple, safe, and effective.

Most treatments rely on supplementing your low hormone levels with artificial hormones. These hormones will replace what your body isn’t producing on its own and help return your body’s functions to normal.

Hypothyroidism is a fairly common condition. About 4.6 percent of Americans ages 12 years old and up have hypothyroidism. Overall, about 10 million people in the United States live with the condition.

The disease gets more common with age. People over 60 years old experience it more frequently.

Women are more likely to have an underactive thyroid. In fact, 1 in 8 women will develop hypothyroidism.

The signs and symptoms of hypothyroidism vary from person to person. The severity of the condition also affects which signs and symptoms appear and when. The symptoms are also sometimes difficult to identify.

Early symptoms can include weight gain and fatigue. Both become more common as you age, regardless of your thyroid’s health. You may not realize that these changes are related to your thyroid until more symptoms appear.

The most common signs and symptoms of hypothyroidism include:

For most people, symptoms of the condition progress gradually over many years. As the thyroid slows more and more, the symptoms may become more easily identified. Of course, many of these symptoms also become more common with age in general.

If you suspect your symptoms are the result of a thyroid problem, talk with your doctor. They can order a blood test to determine if you have hypothyroidism. Learn more about the signs and symptoms of hypothyroidism.

If you don’t already have a primary care doctor, you can browse doctors in your area through the Healthline FindCare tool.

Common causes of hypothyroidism are described below.

Hashimoto’s thyroiditis

Your immune system is designed to protect your body’s cells against invading bacteria and viruses. When unknown bacteria or viruses enter your body, your immune system responds by sending out fighter cells to destroy the foreign cells.

Sometimes, your body confuses normal, healthy cells for invading cells. This is called an autoimmune response. If the autoimmune response isn’t regulated or treated, your immune system can attack healthy tissues. This can cause serious medical issues, including conditions such as hypothyroidism.

Hashimoto’s thyroiditis is an autoimmune condition and the most common cause of an underactive thyroid in the United States. This disease attacks your thyroid gland and causes chronic thyroid inflammation. The inflammation can reduce thyroid function.

It affects middle-aged women most commonly, but it can occur in men and children. This condition also runs in families. If a family member has been diagnosed with the disease, then your risk for having it is higher.

Treatment for hyperthyroidism

If your thyroid gland produces too much thyroid hormone, you have a condition known as hyperthyroidism. Treatment for this condition aims to reduce and normalize thyroid hormone production.

Sometimes, treatment can cause the levels of your thyroid hormone to remain low permanently. This often occurs after treatment with radioactive iodine.

Surgical removal of your thyroid

If your entire thyroid gland is removed as a result of thyroid problems, you’ll develop hypothyroidism. Using thyroid medication for the rest of your life is the primary treatment.

If only a portion of the gland is removed, your thyroid may still be able to produce enough hormones on its own. Blood tests will help determine how much thyroid medication you’ll need.

Radiation therapy

If you’ve been diagnosed with cancer of the head or neck, lymphoma, or leukemia, you may have undergone radiation therapy. Radiation used for the treatment of these conditions may slow or halt the production of thyroid hormone. This will almost always lead to hypothyroidism.

Medications

Several medicines may lower thyroid hormone production, leading to hypothyroidism. These include ones used to treat psychological conditions, cancer, or heart disease, such as:

Factors that can increase your risk of developing hypothyroidism include:

  • being female
  • being at least 60 years old
  • having a family history of hypothyroidism
  • having certain autoimmune conditions, such as Sjögren syndrome and type 1 diabetes

Two primary tools are used to determine if you have hypothyroidism, a medical evaluation and blood tests.

Medical evaluation

Your doctor will complete a thorough physical exam and medical history. They’ll check for physical signs of hypothyroidism, including:

In addition, your doctor will ask you to report any symptoms you’ve been experiencing, such as fatigue, depression, constipation, or constantly feeling cold.

If you have a known family history of thyroid conditions, tell your doctor during this exam.

Blood tests

Blood tests are the only way to reliably confirm a diagnosis of hypothyroidism.

A thyroid-stimulating hormone (TSH) test measures how much TSH your pituitary gland is creating:

  • If your thyroid isn’t producing enough hormones, the pituitary gland will boost TSH to increase thyroid hormone production.
  • If you have hypothyroidism, your TSH levels will be high, as your body is trying to stimulate more thyroid hormone activity.
  • If you have hyperthyroidism, your TSH levels will be low, as your body is trying to stop excessive thyroid hormone production.

A thyroxine (T4) level test is also useful in diagnosing hypothyroidism. T4 is one of the hormones directly produced by your thyroid. Used together, T4 and TSH tests help evaluate thyroid function.

Typically, if you have a low level of T4 along with a high level of TSH, you have hypothyroidism. However, there’s a spectrum of thyroid disease. Other thyroid function tests may be necessary to properly diagnose your condition.

Hypothyroidism is a lifelong condition. For many people, medication reduces or alleviates symptoms.

Hypothyroidism is best treated by using levothyroxine (Levoxyl, Synthroid). This synthetic version of the T4 hormone copies the action of the thyroid hormone your body would normally produce.

The medication is designed to return adequate levels of thyroid hormone to your blood. Once hormone levels are restored, symptoms of the condition are likely to disappear or at least become much more manageable.

Once you start treatment, it takes several weeks before you begin feeling relief. You’ll require follow-up blood tests to monitor your progress. You and your doctor will work together to find a dose and a treatment plan that best addresses your symptoms. This can take some time.

In most cases, people with hypothyroidism must remain on this medication their entire lives. However, it’s unlikely you’ll continue to take the same dose, especially if you have Hashimoto’s thyroiditis. To make sure your medication is still working properly, your doctor should test your TSH levels yearly.

If blood levels indicate the medicine isn’t working as well as it should, your doctor will adjust the dose until a balance is achieved.

Animal extracts that contain thyroid hormone are available. These extracts come from the thyroid glands of pigs. They contain both T4 and triiodothyronine (T3).

If you take levothyroxine, you’re only receiving T4. However, that’s all you need because your body is capable of producing T3 from the synthetic T4.

These alternative animal extracts often contain inconsistent amounts of each hormone, and studies haven’t shown them to be better than levothyroxine. For these reasons, they aren’t routinely recommended.

You can also purchase glandular extracts in some health food stores. These products aren’t monitored or regulated by the Food and Drug Administration (FDA). Because of this, their potency, legitimacy, and purity aren’t guaranteed.

Use either of these products at your own risk. However, do tell your doctor if you decide to try these products so they can adjust your treatment accordingly. , such as selenium and vitamin B.

Complications of hypothyroidism include:

Hypothyroidism can also result in infertility or pregnancy-related complications such as preeclampsia. Find out more about the complications of hypothyroidism.

As a general rule, people with hypothyroidism don’t have a specific diet they should follow. However, here are some recommendations to keep in mind.

Eat a balanced diet

Your thyroid needs adequate amounts of iodine in order to fully function, but you don’t need to take an iodine supplement for that to happen.

A balanced diet of whole grains, beans, lean proteins, and colorful fruits and vegetables should provide enough iodine. Discover other iodine-rich foods.

Monitor your soy intake

Soy may hinder the absorption of thyroid hormones. If you drink or eat too many soy products, you may not be able to properly absorb your medication.

It’s especially important that caregivers monitor the soy intake of infants who need hypothyroidism treatment and also drink soy formula.

Soy is found in:

  • tofu
  • vegan cheese and meat products
  • soy milk
  • soybeans
  • soy sauce

You need steady doses of the medication to achieve even levels of thyroid hormone in your blood. Avoid eating or drinking soy-based foods for at least 4 hours before and after you take your medication.

Be smart with fiber

Like soy, fiber may interfere with hormone absorption. Too much dietary fiber may prevent your body from getting the hormones it needs.

Fiber is vital, so don’t avoid it entirely. Instead, avoid taking your medicine within several hours of eating high fiber foods.

Don’t take thyroid medication with other supplements

If you take supplements or medications in addition to thyroid medications, try to take them at different times. Other medications can interfere with absorption, so it’s best to take your thyroid medication on an empty stomach and without other medications or foods.

The bottom line

Being diagnosed with hypothyroidism doesn’t mean you’ll have to follow a strict diet, although a few adjustments may be necessary.

Even if you’re undergoing treatment, you may deal with long-lasting issues or complications because of the condition. However, there are ways to lessen the effect of hypothyroidism on your quality of life.

Monitor for other health conditions

There’s a link between other autoimmune diseases and hypothyroidism. Hypothyroidism often goes along with other conditions, such as:

Develop fatigue coping strategies

Despite taking medication, you may still experience fatigue from time to time. To help you combat low energy levels, it’s important that you:

Talk it out

Having a chronic medical condition can be difficult, especially if it’s accompanied by other health concerns. Find people you can openly express your feelings and experiences to. This can be a therapist, close friend, family member, or a support group of other people living with this condition.

Many hospitals sponsor meetings for people with conditions such as hypothyroidism. Ask for a recommendation from your hospital’s education office, and attend a meeting. You may be able to connect with people who understand exactly what you’re experiencing and can offer a guiding hand. Learn more about how hypothyroidism can affect your relationships.

When levels of thyroid hormones are low, your body’s natural functions slow down and lag. This causes a variety of symptoms, including fatigue, weight gain, and even depression. A 2016 study found that 60 percent of people with hypothyroidism exhibited some symptoms of depression.

Some people with hypothyroidism may only experience mood difficulties. This can make diagnosing hypothyroidism difficult. Instead of only treating the brain, doctors should also consider testing for and treating an underactive thyroid.

Depression and hypothyroidism share several symptoms. These include:

The two conditions also have symptoms that may distinguish them from one another. For hypothyroidism, problems such as dry skin, constipation, high cholesterol, and hair loss are common. For depression alone, these conditions wouldn’t be expected.

Depression is often a diagnosis made based on symptoms and medical history. Low thyroid function is diagnosed with a physical exam and blood tests. To see if there’s a link between your depression and your thyroid function, your doctor can order these tests for a definitive diagnosis.

If your depression is caused only by hypothyroidism, correcting the hypothyroidism should treat the depression. If it doesn’t, your doctor may prescribe medications for both conditions.

They’ll slowly adjust your doses until your depression and hypothyroidism come under control. Explore the link between thyroid conditions and depression here.

While hypothyroidism has long been associated with depression, a 2016 study indicates it may be associated with anxiety too.

Researchers evaluated 100 people between the ages of 18 and 45 years old who have a known history of hypothyroidism. Using an anxiety questionnaire, they found that around 63 percent of them met the criteria for some form of anxiety.

Research to date has consisted of small studies. Larger and more focused studies on anxiety may help determine if a true connection exists between hypothyroidism and anxiety.

It’s important for you and your doctor to discuss all your symptoms when being evaluated for thyroid conditions.

Women who have hypothyroidism and wish to become pregnant face a particular set of challenges. Low thyroid function or uncontrolled hypothyroidism during pregnancy can cause:

If you have hypothyroidism and are pregnant, it’s important to take the following steps during the time you’re expecting:

Talk to your doctor about testing

Women can develop hypothyroidism while they’re pregnant. Some doctors routinely check thyroid levels during pregnancy to monitor for low thyroid hormone levels. If your levels are lower than they should be, your doctor may suggest treatment.

Some women who never had thyroid problems before they were pregnant may develop them after having a baby. This is called postpartum thyroiditis. For many women, the condition resolves within 12 to 18 months, and medication is no longer required. Approximately 20 percent of women with postpartum thyroiditis will go on to require long-term therapy.

Stay up to date with your medication

Continue to take your medication as prescribed. It’s common to have frequent testing so your doctor can make any necessary adjustments to your thyroid medication as your pregnancy progresses. This ensures that the baby is getting enough thyroid hormone for organ development.

Eat well

Your body needs more nutrients, vitamins, and minerals while you’re pregnant. Eating a well-balanced diet and taking multivitamins while pregnant can help you maintain a healthy pregnancy.

The bottom line

Women with thyroid problems can and very often do have healthy pregnancies.

Your thyroid is responsible for many of your body’s daily functions, including metabolism, organ function, and temperature control. When your body doesn’t produce enough thyroid hormone, all of these functions can slow down.

If your thyroid gland doesn’t function properly, your basal metabolic rate may be low. For that reason, an underactive thyroid is commonly associated with weight gain. The more severe the condition is, the greater your weight gain is likely to be.

The typical amount of weight gain isn’t very high, though. Most people will gain somewhere between 5 and 10 pounds.

Properly treating the condition can help you lose any weight you gained while your thyroid levels were uncontrolled. However, keep in mind that that’s not always the case. Symptoms of underactive thyroid, including weight gain, develop over a long period of time.

It’s not uncommon for people with low thyroid hormone levels to lose no weight after they’re treated for the condition. That doesn’t mean the condition isn’t being properly treated. Instead, it may indicate that your weight gain was the result of lifestyle choices rather than low hormone levels.

Once you’re treated for this condition, you may lose any weight that you’ve gained. That’s because once your thyroid levels are restored, your ability to manage your weight returns to normal.

If you’re treating hypothyroidism but don’t see a change in your weight, that doesn’t mean weight loss is impossible. Work with a doctor, registered dietitian, or personal trainer to develop a focused healthy-eating plan and exercise strategy that can help you lose weight. Get more tips on managing your weight when you have hypothyroidism.

Your body naturally goes through changes as you get older. If you notice a significant difference in how you feel or how your body’s responding, talk to your doctor to see if a thyroid problem may be affecting you. Explore the effects of hypothyroidism on the body.