Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormones. This can affect various parts of the body.

The thyroid gland produces hormones that help the body use energy effectively. With hypothyroidism, the thyroid gland does not produce enough of these hormones. This can affect body weight, mental health, heart function, and more.

Individuals with hypothyroidism may experience a range of symptoms. Tiredness, dry skin, cold sensitivity, and muscle pain can all occur. These symptoms may indicate hypothyroidism’s effects on certain bodily functions.

This article reviews the effects of hypothyroidism on various body systems.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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The circulatory and cardiovascular system manages heart function and blood flow. Hypothyroidism can alter heart rhythm, affect blood pressure, and change the way the heart muscle contracts. It can also cause or worsen other medical issues, including:

A recent study examined heart health among people with hypothyroidism. Those with untreated hypothyroidism had an 83% higher risk of heart problems than individuals whose condition was treated.

People with hypothyroidism should talk with a healthcare professional to learn more. Prompt treatment for this condition can help reduce the risk of heart problems occurring.

Learn more about how hypothyroidism can affect heart rate.

The endocrine system is responsible for producing hormones. Hormones are chemical messengers that manage many functions in the body.

The thyroid gland is one part of the endocrine system. When it is functioning correctly, it helps maintain a healthy metabolism.

Hypothyroidism causes the body to not produce enough thyroid hormones. This can lead to negative effects on:

  • weight
  • body temperature
  • energy
  • skin, hair, and nail health

When the thyroid gland does not function correctly, it can disrupt the entire endocrine system.

Learn about weight loss with hypothyroidism.

Hypothyroidism can also affect the respiratory system, which is how a person breathes. People with hypothyroidism may experience respiratory symptoms, including:

Research has also shown that hypothyroidism can block airways during sleep, leading to sleep apnea. Reduced levels of thyroid hormones may weaken respiratory muscles. They can also alter lung capacity.

Thyroid hormones play an important role in the central nervous system (CNS). These hormones support nerve cells and help regulate energy use. Insufficient levels of these hormones can trigger or worsen conditions related to the CNS. These may include:

In certain cases, hypothyroidism can cause neurological issues. For example, one case study identified neurological symptoms in a male with hypothyroidism. This individual presented with paralysis and weakness on the left side of his face. He also experienced speaking difficulties.

Medical tests identified nerve damage as the root of these symptoms, and this damage was a result of hypothyroidism.

Learn about the link between the thyroid and depression.

Thyroid hormones help the female reproductive system function. These hormones support the growth of the ovaries, placenta, and uterus. Because of this, females with hypothyroidism may experience:

In certain cases, hypothyroidism may negatively affect the health of a developing fetus.

Hypothyroidism can also affect the male reproductive system. Researchers have found that this condition can reduce testosterone levels among males. It can also have negative effects on semen quality.

Hypothyroidism can have an effect on the digestive system. This can include negative effects on metabolism, which is how the body uses energy. When the thyroid does not produce enough hormones, it can reduce metabolism. This can lead to weight gain.

Individuals with hypothyroidism may also be sensitive to certain minerals. For example, foods that contain large amounts of iodine can worsen hypothyroidism symptoms in certain cases.

Learn about foods to eat and avoid with hypothyroidism.

The symptoms of hypothyroidism can vary from person to person. Some common symptoms may include:

Hypothyroidism can also contribute to additional health complications, such as high cholesterol and an enlarged thyroid.

Anyone experiencing symptoms or possible complications of hypothyroidism should speak with a healthcare professional.

The following are some questions people frequently ask about hypothyroidism.

What are some effects of hypothyroidism?

The effects of hypothyroidism may include:

  • fertility issues
  • heart problems
  • nerve damage

Getting prompt, effective treatment for hypothyroidism is important. Receiving treatment for hypothyroidism can help reduce the risk of complications.

What are the worst symptoms of hypothyroidism?

Each person with hypothyroidism experiences a unique set of symptoms and complications. Because of this, the “worst” symptoms may vary between individuals. These may include:

  • depression
  • extreme sensitivity to cold
  • fertility issues and heavy, irregular periods
  • fatigue

How does hypothyroidism make people feel?

The experience of hypothyroidism depends on the individual. Some people may experience issues with feeling exhausted or sluggish. Others may experience mental health issues such as depression. Nerve complications can cause pain or numbness in the arms or legs.

Treatment can help with most symptoms. A person can speak with a healthcare professional about any concerns or new or worsening symptoms.

Hypothyroidism means the thyroid gland does not produce enough hormones. It can have an effect on many different parts of the body.

Individuals with hypothyroidism may develop heart problems or have difficulty breathing. They may also experience fertility issues or complications that affect the nervous system.

Anyone with hypothyroidism should inform their doctor about new or worsening symptoms. Treatment can help reduce the risk of complications occurring.