Symptoms of hyperthyroidism: how to recognise the signs of hyperthyroidism

In hyperthyroidism, the thyroid gland produces excessive amounts of hormones that speed up the metabolism. But what happens if this condition goes unrecognised and what are the signs? Sudden, unexplained weight loss can be the first sign. Read on to find out more about the signs and consequences of hyperthyroidism. 

Table of Contents

• What is hyperthyroidism?
• How can you recognize an overactive thyroid?
• Can hyperthyroidism cause weight loss?
• What are complications of hyperthyroidism?
• How is hyperthyroidism diagnosed?
• Summary

What is hyperthyroidism?

In hyperthyroidism, the thyroid gland produces excessive amounts of hormones, which speed up the body’s metabolism. But what happens if this condition goes undetected, and what signs should you look out for? A sudden, unexplained weight loss can be one of the first signs. Read on to learn more about the symptoms and consequences of hyperthyroidism. With the Homed-IQ thyroid test, you can conveniently check from home whether you may have an overactive thyroid—without needing to make a doctor’s appointment.

The thyroid is one of the most important glands in the body. It is butterfly-shaped and located just below the larynx at the front of the neck. It is responsible for producing hormones that regulate metabolism and many other vital bodily functions.

The two main hormones produced by the thyroid are thyroxine (T4) and triiodothyronine (T3). These hormones play a crucial role in regulating a number of bodily functions, including:

• Energy metabolism

• Growth and development

• Body temperature

• Heart rate

Hyperthyroidism occurs when the thyroid becomes overactive and produces more hormones than the body needs. This imbalance can speed up many normal bodily processes, leading to a wide range of symptoms.

The causes of hyperthyroidism can vary and include benign thyroid tumors (adenomas), inflammation, or autoimmune diseases such as Graves’ disease, in which the immune system mistakenly attacks the thyroid, causing it to produce excess hormones (NIDDK, 2021).

How can you recognize an overactive thyroid?

Symptoms of hyperthyroidism are diverse and may vary. One of the most noticeable and often earliest signs is a sped-up metabolism. Common initial symptoms include heart palpitations, unexplained weight loss, nervousness, and excessive sweating. Other symptoms can be grouped as follows:

Heart and circulatory system

• Increased heart rate

• Heart palpitations

• High blood pressure

Digestive system

• Increased bowel movements, diarrhea

• Weight loss despite a good appetite

• Increased appetite

Nervous system

• Nervousness, tremors, restlessness

• Difficulty concentrating

• Sleep disturbances

Skin and hair

• Heat sensitivity

• Sweating

• Thinning hair

Eyes

• Bulging eyes

• Double vision

• Eye pain

Source: American Thyroid Association, 2023; Mayo Clinic, 2021

Can hyperthyroidism cause weight loss?

Sudden, unexplained weight loss can often seem like a pleasant surprise—especially when appetite has actually increased. However, this phenomenon may be a result of hyperthyroidism, which drives the metabolism into overdrive due to elevated hormone levels. While hypothyroidism (an underactive thyroid) can cause weight gain, an overactive thyroid increases calorie consumption. It is therefore important to pay attention to such physical changes ( Cleveland Clinic, 2021). 

What are complications of hyperthyroidism?

If left untreated for a longer period, hyperthyroidism can lead to serious health issues. Some of the possible complications include:

• Atrial fibrillation: A type of heart rhythm disorder where the heart beats irregularly and often very quickly. This can increase the risk of stroke and lead to heart failure.

• Osteoporosis: Osteoporosis reduces bone density, making bones weaker and more prone to fractures. Excess thyroid hormones can accelerate bone loss, increasing the risk of developing osteoporosis.

• Thyroid storm (thyrotoxic crisis): A rare but life-threatening condition that can occur when hyperthyroidism is untreated or poorly managed. It may be triggered by infections, pregnancy, or incorrect medication use. Symptoms include rapid heartbeat and loss of consciousness. Suspected thyroid storm is a medical emergency and requires immediate help.

• Muscle weakness and loss: Excess thyroid hormones can lead to muscle tissue breakdown, especially in the thighs, causing difficulties in standing up, walking, or climbing stairs.

• Eye problems: People with hyperthyroidism—particularly those with Graves’ disease—may develop bulging or inflamed eyes, leading to pain, redness, and vision disturbances.

• Red, swollen skin: In rare cases, especially in Graves’ disease, the skin—usually on the shins and feet—can become red and thickened.

If you notice signs or symptoms of hyperthyroidism, you should urgently consult a doctor to explore further testing and potential treatment (NHS, 2023). 

How is hyperthyroidism diagnosed?

Diagnosis typically begins with a review of clinical symptoms and a physical examination by a doctor. One of the most important ways to confirm the diagnosis is through a blood test that measures the levels of thyroid hormones in the blood ( MedlinePlus, 2021). 

Want to check for yourself?

The Homed-IQ thyroid test offers a convenient way to check thyroid function from home. This test measures levels of TSH, T3, and T4—critical indicators of thyroid health. Imbalanced levels can indicate either hyperthyroidism or hypothyroidism. With easy handling and the ability to view results online, Homed-IQ provides an efficient and user-friendly way to gain insights into your thyroid function and potentially avoid complications early on. It is strongly recommended to consult a doctor if results are abnormal, to ensure proper treatment or rule out underlying conditions.

Summary

Hyperthyroidism is a condition in which the thyroid gland produces too many hormones, affecting various systems in the body. Symptoms include heart palpitations, weight loss, nervousness, and eye issues. It is important to recognize these signs and see a doctor if necessary. If left untreated, hyperthyroidism can lead to serious health complications.