Hypothyroidism is a common condition in which the thyroid does not produce and release enough thyroid hormone into your bloodstream. This slows down your metabolism. Also called an underactive thyroid, hypothyroidism can make you feel tired, overweight, and unable to tolerate cold temperatures. The main treatment for hypothyroidism is hormone replacement therapy.

What is hypothyroidism?

Hypothyroidism is a condition in which there is not enough thyroid hormone in your blood and your metabolism slows down.

Hypothyroidism occurs when your thyroid does not produce and release enough thyroid hormone from your body. This slows down your metabolism, affecting your whole body. Also known as dysfunctional thyroid disease, hypothyroidism is common.

If your thyroid levels are very low, this is called myxedema. In severe cases, myxedema can cause severe symptoms, including:

• Low body temperature.
• Heart failure.

This severe form of hypothyroidism is dangerous to health.

Generally, hypothyroidism is a highly treatable condition. It can be managed with regular medication and follow-up consultation with your healthcare provider.

How does the thyroid work?

The thyroid is a small butterfly-shaped organ located in front of your neck under the vocal cords (throat). Imagine in the center of a butterfly’s body-centered around your neck, its wings encircling the trachea (trachea). The main function of the thyroid is to control your metabolism. Metabolism is the process by which your body converts food into energy that your body uses to function. The thyroid gland produces the hormones T4 and T3 to control your body. These hormones work throughout the body to tell the body cells how much energy to use. They control your body temperature and heart rate.

When your thyroid is functioning properly, it constantly makes hormones, releases them, and makes new hormones to replace the used ones. This keeps your metabolism active and all your body systems are fine. The amount of thyroid hormones in the blood is controlled by the pituitary gland, located in the middle of the skull below the brain. When the pituitary gland feels a thyroid hormone deficiency or overdose, it fixes its hormone (thyroid hormone stimulating hormone, or TSH) and sends it to the thyroid to measure values.

If the level of thyroid hormones is too high (hyperthyroidism) or too low (hypothyroidism), the whole body is affected.

Who is affected by hypothyroidism?

Hypothyroidism can affect people of all ages, genders, and races. It is a common condition, especially for women over 60 years of age. Women often have a higher risk of developing hypothyroidism after menopause than ever before in life.

What is the difference between hypothyroidism and hyperthyroidism?

In hypothyroidism, the thyroid does not make enough thyroid hormones.

The difference between hypothyroidism and hyperthyroidism is size. In hypothyroidism, the thyroid produces very little thyroid hormone. On the other hand, a person with hyperthyroidism has an overactive thyroid hormone. Hyperthyroidism involves high levels of thyroid hormones, which make your body faster. If you have hypothyroidism, your metabolism slows down.

Many things are at odds between these two situations. If you have hypothyroidism, you may have a hard time coping with the flu. If you have hyperthyroidism, you can not manage the heat. They are the opposite of an overactive thyroid. Ideally, you should be in the middle. Treatment for both conditions works to keep your thyroid function as close to the center as possible.

SYMPTOMS AND CAUSES

What causes hypothyroidism?

Hypothyroidism can have a primary or secondary cause. The main reason is a condition that directly affects the thyroid gland and causes it to cause low levels of thyroid hormones. The second reason is that the pituitary gland fails, which means it is unable to send thyroid-stimulating hormone (TSH) to the thyroid to balance thyroid hormones.

The main causes of hypothyroidism are very common. The most common of these underlying causes is an autoimmune disease called Hashimoto’s disease. Also called Hashimoto’s thyroiditis or chronic lymphocytic thyroiditis, this is hereditary (passed on in the family). In Hashimoto’s disease, the immune system attacks and damages the thyroid gland. This prevents the thyroid gland from making and releasing enough thyroid hormone.

Other major causes of hypothyroidism may include:

• Thyroiditis (inflammation of the thyroid).
• Treatment of hyperthyroidism (radiation and surgical removal of the thyroid).
• Iodine deficiency (lack of enough iodine – a mineral used by the thyroid gland to make hormones – in your body).
• Genetic conditions (health status passed on to your family).
• In some cases, thyroiditis can occur after pregnancy (postpartum thyroiditis) or an infection caused by a virus.

What causes hypothyroidism during pregnancy?

In most cases, women with hypothyroidism during pregnancy have Hashimoto’s disease. This autoimmune disease causes the immune system to attack and damage the thyroid gland. When that happens, the thyroid is unable to produce and release high levels of thyroid hormones, which affect the entire body. Pregnant women with hypothyroidism may feel very tired, have a hard time coping with cold temperatures, and suffer from muscle cramps.

What are the symptoms of hypothyroidism?

Symptoms of hypothyroidism usually develop slowly over time – sometimes for years. Can include:

• Feeling tired (fatigue).
• You experience numbness and stinging in your hands.
• Gaining weight.
• Pain throughout your body (may include muscle weakness).
• Having high blood cholesterol levels is normal.
• Feeling depressed.
• Inability to tolerate cold temperatures.
• Having dry, rough skin and hair.
• You are experiencing diminished sexual interest.
• Having frequent and difficult menstrual periods.
• Seeing body changes on your face (including drooping eyelids, and puffy eyes and face).
• To make your voice lower and hoarse.
• Feeling more forgetful (“brain fog”).