Hypothyroidism – Symptoms, Causes, and Treatment

Energy Decreases, Thinking Slows Down, and the Body Becomes More Sensitive to Cold — Often, the Cause is Hypothyroidism

Hypothyroidism is a condition in which the thyroid gland fails to produce enough thyroid hormones (T4/T3) necessary for the body to function properly. This leads to dysfunction throughout the body. This is how the American Thyroid Association and the U.S. National Institutes of Health explain the condition.

The Most Common Cause? Autoimmune Disease — Hashimoto’s Thyroiditis

In most cases, hypothyroidism is caused by an autoimmune process — Hashimoto’s disease. In this condition, the immune system attacks the thyroid gland. Other causes include surgical removal of the thyroid, radiation therapy, and iodine deficiency. Due to these causes, hypothyroidism is a common diagnosis in many countries.

Why is Early Detection So Important?

Hypothyroidism is not just about discomfort or fatigue — it is a source of systemic metabolic changes. Thyroid hormones regulate lipid metabolism, so their deficiency often raises cholesterol levels and increases the risk of cardiovascular disease. These levels often improve once proper treatment is started.

Timely diagnosis is especially critical during pregnancy. Untreated or poorly controlled hypothyroidism increases the risks of miscarriage, preeclampsia, and placental abnormalities. That’s why women who are planning pregnancy or are at high risk during pregnancy should monitor their hormone levels and begin therapy as needed.

In rare but severe cases, long-untreated hypothyroidism can lead to myxedema crisis — a life-threatening condition requiring immediate intensive treatment.

The Nervous System and Thyroid Hormones

Thyroid hormones play a vital role in managing the nervous system. Decreased energy, lack of motivation, and difficulty concentrating are often linked to hormone deficiency. Research has shown that proper and timely therapy can reverse these cognitive symptoms.

Symptoms of Hypothyroidism – Why Does the Body "Tire Out"?

The first signs are often subtle: waking up already tired, feeling low energy during the day, and becoming uncomfortably cold in the evening. Chronic fatigue, weight gain, and cold intolerance are often mistaken for simple exhaustion or seasonal effects — when in fact, they may be symptoms of hypothyroidism.

Skin and hair changes are additional signs: dryness, hair loss, and brittle nails. Women may experience menstrual irregularities and fertility issues. Some patients develop a slower heart rate, and constipation is also common.

Muscles are another “frontline” affected. Hypothyroid-related myopathy develops slowly and is often attributed to other factors, such as a sedentary lifestyle. Emotional changes also occur: irritability, decreased motivation, lack of focus, and even symptoms of depression are common among hypothyroid patients.

Symptoms of hypothyroidism often go unnoticed because they are nonspecific and can be present in otherwise healthy individuals. The disease also progresses slowly, leading many people to adapt to this “new normal.” That’s why only blood tests can provide a definitive diagnosis.

Autoimmune Thyroiditis – What is Hashimoto’s Disease?

One of the common causes of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s disease. In this condition, the immune system begins to damage the thyroid gland: antibodies (anti-TPO, anti-Tg) are produced, which gradually destroy healthy tissue. As a result, the gland loses its ability to produce hormones, leading to hypothyroidism.

In early stages, symptoms may be absent. Antibodies may already be positive, but hormone levels can still be normal. That’s why autoimmune thyroiditis is considered one of the most “silent” diseases.

For diagnosis, TSH is measured first, and if needed, FT4. If TSH is elevated, an anti-TPO test is usually performed. Repeated antibody monitoring is not necessary, as the main focus of treatment is TSH level control. Ultrasound is also not always required unless there is suspicion of a thyroid nodule or if antibodies are negative.

In Hashimoto’s disease, ultrasound often reveals a hypoechogenic, heterogeneous gland.

How to Overcome Hypothyroidism – Treatment and Lifestyle Changes

Naturally, the first question patients ask after diagnosis is: how can I overcome hypothyroidism? Treatment must be managed by an endocrinologist, who will assess symptoms and risks, prescribe the necessary tests (TSH/FT4, and antibodies if needed), and determine monitoring intervals to keep hormone levels stable.

Self-treatment and reliance on “generic protocols” are risky — over- or under-treatment can affect the heart, bones, and metabolism.

While medication is the foundation of treatment, diet and physical activity enhance results. That’s why it's important to adopt a healthy diet, incorporate physical activity into your routine, and ensure you get the right nutrients and minerals from your food.

Hypothyroidism vs. Hyperthyroidism — What's the Difference?

In medical terminology, “hypo” refers to a deficiency, while “hyper” refers to excess. In hypothyroidism, the body produces too little hormone. As a result, everything slows down: fatigue, cold intolerance, weight gain, and dry skin are common complaints.

In contrast, hyperthyroidism speeds everything up — causing rapid heartbeat, anxiety, sweating, and weight loss despite increased appetite.

Naturally, treatment differs: hypothyroidism requires hormone replacement and nutritional support, while hyperthyroidism is treated with antithyroid medications.

Hypothyroidism in Children and Pregnant Women

Congenital hypothyroidism in children is especially dangerous. Without treatment, brain and physical development can be irreversibly impaired. That’s why many countries implement universal newborn screening. Once diagnosed, treatment should begin immediately — in newborns, no later than two weeks after birth. This “golden window” allows for normal intellectual development.

During pregnancy, hypothyroidism control is critical for both mother and baby. Doses often need to be increased by 20–30%, and monitoring should be done every 4–6 weeks. Without treatment, the risks of miscarriage, preeclampsia, and developmental delays in the fetus increase significantly. Close monitoring by both an endocrinologist and a gynecologist is essential during this period.

The Importance of Timely Action

Thyroid disorders begin quietly and gradually rob us of our energy. Timely diagnosis of hypothyroidism protects patients from cardiovascular complications — and in pregnancy, safeguards the health of both mother and child.

If symptoms appear, the steps are simple:
– First, consult a doctor, explain your condition, and they will determine which tests are needed.
– Make sure to undergo all the tests your doctor recommends.
– If necessary, follow up with an endocrinologist and get an ultrasound.

Most importantly, strictly follow the treatment plan. A single doctor’s visit and the right test can make a huge difference — timely diagnosis and proper treatment restore the body to a rhythm where we feel natural, energetic, and calm again.