Can hyperthyroidism cause weight gain?
Team Gabit
6 months ago | 5 mins

Can hyperthyroidism cause weight gain?

If you’ve ever wondered “does hypothyroidism cause weight gain?”, this comprehensive guide provides answers. Understand the connection between thyroid and weight fluctuations, its impact and effective weight management strategies.

On a path towards optimal health, a plethora of variables are thrown at us to get through. On some days, it might feel like we are headed to nowhere and that our body has a mind of its own. One of these variables that comes along the way and is often underestimated is the thyroid gland. When this tiny heart-shaped gland goes awry, it disrupts the hormonal balance in our body. This happens when the thyroid gland is overactive and produces too many thyroid hormones, known as hyperthyroidism. 

These hormones are important for controlling metabolism, the synthesis of energy, and many other body processes.  Contrary to popular assumptions, weight loss is not the only result of such a condition. Very rarely, hyperthyroidism causes weight gain too. 

know how hyperthyroidism causes weight gain

What is hyperthyroidism? 

The thyroid gland is an organ situated in the front of the neck that produces hormones called Triiodothyronine (T3) and thyroxine (T4). These hormones are essential for controlling the body's energy levels, metabolism, and other physiological processes.

This leads us to the question - “What is hyperthyroidism and can hyperthyroidism cause weight gain?” Hyperthyroidism is characterised by an overactive thyroid gland that produces an excessive amount of thyroid hormones. Thus, the body's metabolic process speeds up when the thyroid gland generates too many thyroid hormones.

know how hyperthyroidism causes weight gain

How hyperthyroidism function can affect your weight

Owing to its impact on the body's metabolism (a process that converts food into energy), hyperthyroidism can significantly affect body weight. During hyperthyroidism, the body produces an excess amount of T3 and T4 hormones and raises the metabolism in the body. In very few cases hyperthyroidism causes weight gain. It is usually accompanied with a rapid weight loss. The increased metabolism has a number of impacts that influence fluctuations in weight

  • Excess energy expenditure: The body burns more calories at rest as a result of the faster metabolism. Even in the absence of physical activity, this higher energy expenditure results in weight loss.
  • Changes in appetite: While some hyperthyroidism patients may feel more hungry than usual, others may not feel hungry at all. Due to a higher metabolic rate, weight reduction happens even with an increased calorie intake.
  • Muscle breakdown: Hyperthyroidism causes the loss of muscle mass. The body may use the breakdown of muscle proteins as fuel in an attempt to fulfil the increased energy demands. It is later followed by weight loss and muscle atrophy.
  • Nutrient malabsorption: An impaired digestive system can cause malabsorption of nutrients. Even when a person consumes normal or an increased amount of calories, the body may refuse to absorb these nutrients adequately, causing weight loss.
know how hyperthyroidism causes weight gain

What are the symptoms of hyperthyroidism?

When considering can hyperthyroidism cause you to gain weight, look out for these symptoms:

  • Grumpiness or anxiety: Overproduction of thyroid hormones can have an impact on the nervous system, which increases anxiety and irritability. People could experience jitters or anxiety.
  • Tremors: Fine tremors, particularly in the hands and fingers, can be brought on by elevated metabolic activity in the body. You might notice these tremors when handling objects or using fine motor skills.
  • Lack of energy: Hyperthyroidism usually results in a faster metabolism, causing some people to experience weariness as a result of the stress on their bodies.
  • Enlarged thyroid gland (Goitre): Hyperthyroidism can occasionally result in the thyroid gland enlarging, which causes a noticeable bulge in the neck (also known as goitre).
  • Excessive bowel movements: Thyroid hormones have an impact on the digestive system, and an excess can cause diarrhoea or an increase in bowel movements. This could result in dehydration and weight loss.
know how hyperthyroidism causes weight gain

What’s the relationship between thyroid function and body weight?

Can a thyroid problem lead to weight gain? Here’s what experts say -

An essential regulator of the body's metabolic system is situated in the neck and is known as the thyroid gland. Through the synthesis of thyroid hormones, particularly thyroxine (T4) and triiodothyronine (T3), it plays a role in regulating metabolism. This closely relates to body weight.

A hyperactive thyroid produces more thyroid hormones, which raises the metabolic rate. This condition known as hyperthyroidism, causes weight loss. On the other hand, hypothyroidism, or underactive thyroid, causes the metabolism to slow down and may result in weight gain. To add to this, thyroid hormones also affect hunger, nutrient absorption, fluid balance and energy balance in the body.

know how hyperthyroidism causes weight gain

Weight management strategies for individuals with hyperthyroidism

  • Sufficient calorie intake: In spite of a faster metabolism, it's crucial to maintain a sufficient calorie intake to avoid losing too much weight. Consider consulting a nutritionist or dietitian to manage your daily calorie and national intake.
  • Supplementation: Your healthcare professional might suggest supplements to address certain nutritional needs if deficiencies are found. Supplements are advised on each person’s individual needs. Vitamin B, D and calcium are common supplements given.
  • Stress management: Stress can increase the symptoms of hyperthyroidism. Practice stress-reducing strategies such as deep breathing, meditation, or yoga. 
  • Hydration: Dehydration can contribute to weight loss. Stay well hydrated and aim to intake a steady amount of fluids.
  • Regular monitoring: Keep a regular eye on your weight and thyroid levels with advice from your practitioner. This makes it possible to monitor development and make any necessary changes to your lifestyle treatment.

When should you speak to your doctor?

Consult your healthcare practitioner right away if you are exhibiting symptoms of an overactive thyroid. Unexpected weight loss, fast heartbeat, restlessness, anxiety, heat intolerance, perspiration, exhaustion, weakened muscles and an enlarged thyroid gland (goitre) are typical signs of hyperthyroidism. 

Early diagnosis provides for timely treatment. It is imperative that you communicate openly and schedule regular follow-up consultations to ensure efficient management and resolution of any issues or symptoms. 

know how hyperthyroidism causes weight gain


The thyroid gland plays an understated influence on hormonal balance, metabolism and body weight. An overactive thyroid is the hallmark of hyperthyroidism, which can cause metabolic disturbances and weight changes. Effective management requires identifying symptoms like anxiety, dizziness and increased bowel movements. Further, a healthy diet, possible supplements, and stress reduction all play a part in overall well-being. In order to effectively navigate the complexity of hyperthyroidism, prompt medical evaluation for symptoms is essential. 

Frequently Asked Questions

Can hyperthyroidism cause weight gain?

Hyperthyroidism rarely causes weight gain. However, you might gain weight after you start your treatment for hyperthyroidism. If you’re gaining weight for any other reason, it is best to consult your doctor.

Are there any other reasons where hyperthyroidism might cause weight gain?

In most cases, you gain weight during hypothyroidism. Hyperthyroidism causes weight gain only when you start treatment for it. In all other cases, you will not gain weight through hyperthyroidism.

Can treatment for hyperthyroidism lead to weight gain?

Hyperthyroidism causes you to lose weight. Naturally, as you start taking suitable treatments and medicine, you will gain weight to recover the lost pounds.

What should I do if experiencing unexplained weight gain and suspect thyroid issues?

Thyroid, more precisely, hypothyroidism (underactive thyroid gland) could be a possible reason behind weight gain in many individuals. It is recommended that you consult a doctor to understand the specific root cause of your weight gain.

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