Hypothyroidism vs Hyperthyroidism difference

Hypothyroidism vs Hyperthyroidism: Difference, Symptoms & More

Hypothyroidism vs Hyperthyroidism

Hypothyroidism vs hyperthyroidism is one of the most confusing topics. Both are two different diseases. It has different meanings, causes, risks, symptoms.

First, we must know the work of the thyroid and what it is responsible for.

The thyroid gland is one of the essential glands that play a major role in the growth of metabolism. It releases thyroid hormones into the bloodstream which regulates body function. Overall, it helps in the development of the body. Every cell in our body is dependent on the thyroid hormone for the regulation of its metabolism. 

The function of Thyroid Gland

The main function of the thyroid is to consume iodine that is found in varieties of foods and convert it into two main thyroid hormones-

  •  Thyroxine
  • Triiodothyronine

These hormones are required by all the cells in your body to work efficiently. The thyroid gland is the only gland that absorbs iodine. The hormones released to control the metabolism.

Metabolism means the conversion of oxygen and calories that you take from foods into energy.

The two main diseases caused by the thyroid gland are-

Let us talk about it one by one


Hypothyroidism refers to the disease when your thyroid gland does not produce enough hormones. It is a condition of underactive thyroid. The production of hormones is slow. As the production of hormones is slow, the metabolism also becomes slow. 

Symptoms of Hypothyroidism

Symptoms differ from person to person, it depends upon the hormone deficiency. Symptoms develop slowly with time. It takes about a year to properly recognize the disease symptoms. 

In the beginning, you hardly see any symptoms other than weight gain and fatigue. When the deficiency of hormones decreases, eventually the metabolism also decreases which results in serious problems.

Symptoms include-

  • Fatigue
  • Constipation
  • Dry skin
  • Weight gain
  • Muscle weakness
  • Increased blood cholesterol level
  • Thinning hair
  • Depression
  • Goiter (enlarged thyroid)
  • Feeling of cold
  • Irritability
  • Slow heart rate

The early symptoms are anxiety, weight gain, hair loss, trouble in concentration, excessive tiredness, you will be unable to tolerate cold.

Causes of Hypothyroidism

When the thyroid gland does not produce enough hormones it leads to hypothyroidism. There can be many other causes like-

  • Autoimmune disease- It is also called Hashimoto’s thyroiditis. It occurs when the immune system produces antibodies that attack our own tissues. It can be due to genes or environmental conditions. If this happened, it affects the ability of the thyroid gland to produce hormones.
  • Radioactive iodine treatment- When a person suffers from hyperthyroidism (when the thyroid gland produces excessive hormones), it is treated with radioactive iodine. This treatment is done so that the thyroid gland function normally. But sometimes, correcting hyperthyroidism can lead to lower production of hormones, which results in permanent hypothyroidism.
  • Thyroid surgery- When we remove a portion of the thyroid gland, it lowers the productivity of hormones. 
  • Radiation therapy- Radiation treats cancer of the neck and head. This therapy can sometimes affect the thyroid gland and can result in hypothyroidism.
  • Deficiency of iodine in the diet- The thyroid gland absorbs iodine, it needs iodine to produce thyroid hormones. Iodine can be consumed only through diet. If your diet does not include iodine, it can affect hormone production. Iodine can be consumed from dairy products, eggs, saltwater fish.
  • Medication- Numerous medications can lead to hypothyroidism. For instance, lithium is taken to treat a psychiatric disorder. A person must concern a doctor about the effect of the medication on the thyroid gland. 
  • Thyroid problem at birth- Some babies are born with the improper functioning of the thyroid gland. It is called congenital hypothyroidism 
  • Disorder or damage of pituitary gland- Pituitary hormones produces thyroid-stimulating hormones. Which basically informs the thyroid, how many hormones should be produced. If it gets damaged, it can seldom affect the production of thyroid hormones.

Risks Associated With It

Anyone can develop hypothyroidism. It mostly affects women than men. It can be genetic if any person from your family suffers from autoimmune disease. 

  • When we grow older the risk increases
  • If you are women
  • Genetics
  • Treated with radioactive iodine
  • Being pregnant or delivered a baby within the past six months 
  • Diabetes, rheumatoid arthritis, celiac disease
  • Down syndrome

How to know whether we have hypothyroidism

If we have symptoms, the doctor will conduct blood tests to check the level of hormones. Thyroid-stimulating hormone, thyroxine.

If the test result is abnormal, then the doctor will conduct a thyroid scan or ultrasound, to check the inflammation.

Treatment of Hypothyroidism

  • To treat hypothyroidism, doctors will prescribe the human-made thyroid hormone T4. This pill is taken every day. 
  • You have to undergo blood tests regularly to check your thyroid hormone levels.
  • The doctor needs to adjust your medication from time to time.

If hypothyroidism is left untreated there can be many complications.

  • Older women mostly above 60 years are at risk if their hormones level are extremely low.
  • It can lead to goiter, the glands swell and changes the appearance of the neck.
  • It can increase the cholesterol level and can be riskier for the heart.
  • It becomes difficult for girls to conceive because the lower thyroid hormone disrupts egg production.
  • Weight increases because the metabolism becomes slow, which does not burn enough calories.


Hyperthyroidism refers to the disease when your thyroid gland produces an excess of thyroxine. It is a condition of an overactive thyroid. The production of hormones is too much. As the production of hormones is too fast, the metabolism also becomes fast, which converts the calories into energy very soon. This leads to unintentional weight loss.

Symptoms of Hyperthyroidism

When the amount of T3 and T4 increases, the metabolic rate increases, and hence our body shows the following symptoms: 

Causes of Hyperthyroidism

There can be various reasons for developing hyperthyroidism. The most common cause is an autoimmune disorder. It causes the thyroid to secrete too much hormone. It is most common in women than men.

  • It can be genetic.
  • Excess of iodine
  • Excessive intake of tetraiodothyronine through dietary supplements or medication.

How to know whether we have hyperthyroidism

  • The first step is to get a complete physical exam. This will help to know the reason behind-
    • Weight loss
    • Rapid pulse rate
    • High blood pressure
    • Enlarged thyroid gland
  • Other tests can be done to check your cholesterol level, if the cholesterol level is low, this means that the metabolism is too high and it is burning the cholesterol quickly.
  • Another test can be for T4, T3. It measures the level of thyroid hormone in your blood.
  • A thyroid scan can be done, this will help the doctor to know whether the thyroid is overactive. 
  • Doctors can conduct an ultrasound, this will measure the size of the thyroid gland.

Treatment of Hyperthyroidism

  • Medications

Medication like tapazole stops the thyroid from making hormones.

Medicine will be recommended by the doctor. It must be taken every day.

  • Radioactive Iodine

It destroys the cell that produces hormones. Side effects can be dry mouth, dry eyes, sore throat.

  • Surgery

The part of the thyroid can be surgically removed. But proper thyroid hormone supplements must be taken to prevent hypothyroidism.

Things that can be done by you to improve the symptoms

  • Take a proper diet, with proper calcium and sodium which prevents hyperthyroidism.
  • Ask your doctor for proper diet and exercise.
  • It can also weaken the bone, which can lead to osteoporosis. This can be treated by taking vitamin D or calcium supplements.

Difference between Hypothyroidism vs Hyperthyroidism

Hypothyroidism leads to slow metabolism, weight gain, and tiredness. A slow metabolism can slow down the body’s functioning. Whereas in hyperthyroidism, you become more energetic. you experience weight loss. You can feel depressed or anxious too.

The most common difference between hypothyroidism and hyperthyroidism is the hormone levels. In hypothyroidism, the hormone decreases. Whereas in hyperthyroidism, hormone increases.

You look fat in case of hypothyroidism and you look thin in case of hyperthyroidism. 

In conclusion, they both are equally dangerous if left untreated. It can lead to unconsciousness and death. 

Frequently Asked Questions

Let us discuss some common questions.

What are hyperthyroidism and hypothyroidism?

Hyperthyroidism refers to the disease when your thyroid gland produces an excess of hormones. It is basically overactive thyroid. 

Hypothyroidism means when the thyroid gland produces fewer hormones. It is basically underactive thyroid.

Why do we look fat in case of hypothyroidism?

We look fat because the thyroid gland produces fewer hormones, which lowers the metabolism rate. Due to the slow metabolism, calories do not convert into energy which makes us look fat.

Why do we look thin in case of hyperthyroidism?

We look thin because the thyroid gland produces excess hormones, which increases the metabolism rate. Due to the fast metabolism, calories convert into energy too quickly which makes us look thin. 

Can we have symptoms of both hyperthyroidism and hypothyroidism?

Yes, a person may switch from hyperthyroidism to hypothyroidism and vice versa. It can be due to the treatment and other factors.

What are the symptoms of hyperthyroidism?

In case of hyper, you feel nervous, weak or tired, irregular heartbeat, you feel very hot and sweat a lot.

How to boost the production of thyroid hormone?

Eat iodine-rich foods. Eat salted nuts, eggs, dairy products.

What are the warning signs of thyroid-related problems?

Weight gain or loss, hair loss, feeling cold or overheated, anxiety, trouble in concentrating.

Does the thyroid affect the sleeping cycle?

Yes, an overactive thyroid can affect sleep due to irritability and nervousness, and a constant feeling of tiredness. 

What food should be avoided in case of overactive thyroid?

Iodized salt, fish and shellfish, dairy products, iodine supplements.

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