What is Hyperthyroidism?
Hyperthyroidism, or an overactive thyroid, happens when the thyroid gland produces too much of a hormone called thyroxine.
The thyroid gland is situated in the front of the neck, below the voice box, and is shaped like a butterfly. It is responsible for regulating the body’s metabolism and growth. (1)
Hormones released by the thyroid gland affect blood pressure, body temperature, heart rate and weight. (2)
The thyroid gland forms part of the body’s hormone (endocrine) system. When the levels of thyroid hormones are elevated many bodily functions can go into overdrive. The symptoms of this include:
Weight loss can happen when the thyroid is overactive. This might be the case even if you have made no changes to your diet or are eating more than usual.
This is because hyperthyroidism increases your basal metabolic rate (BMR). The more severe the condition, generally, the greater weight loss.
The thyroid also helps control appetite, and this can also increase, consequently some people might actually gain weight. (3)
Rapid Heart Beat
Hyperthyroidism interferes with the regular function of the heart. It can cause heart palpitations or a rapid heart beat.
High Blood Pressure (Hypertension)
The effects hyperthyroidism has on the heart also affects blood pressure. Due to an increased amount of blood pumped by the heart, along with increased heart rate, high blood pressure can be common.
Other contributing factors are: the rate and strength the heart contracts, high pulse pressure, decreased resistance from the veins and increased BMR. (6)
The thyroid system secretes hormones which have a controlling influence on the nervous system. They can either directly or indirectly affect the mechanisms the different body functions use to communicate.
The result is nervousness, trembling, headache, mood disorders and irritability. Hyperthyroidism can also contribute to anxiety disorders and memory issues. (7)
Weakness and Tiredness
Feelings of extreme tiredness and lethargy, as well as muscle weakness are often associated with this condition.
For people visiting a doctor with fatigue, thyroid function is usually one of the first things they will check. This condition increases your metabolism and initially you might have excess energy. However, with time the body slows down and you feel tired.(8, 9)
Muscle wastage and weakness are also common in people with hyperthyroidism. The thyroid helps regulate energy expenditure, thermogenesis (burning calories to produce heat) and growth in the musculoskeletal system. (10)
Enlarged Thyroid (Goiter)
Swelling in the neck might indicate presence of a goiter, an enlargement of the thyroid gland which might have nodules attached. The nodules can range in size from large to small.
Symptoms of a goiter could be coughing, difficulty breathing or swallowing and a hoarse voice. (11)
The thyroid gland and the hormones it releases all play a part in both puberty and menstruation. An overactive thyroid in women might disrupt the menstrual cycle causing less bleeding (hypomenorrhea) or no bleeding (amenorrhea). (12)
Difficulty in both falling and staying asleep, resulting in sleep deprivation can be caused by an overactive thyroid. This will leave people feeling tired and irritable during waking hours. (13)
Sweating and Heat Intolerance
The ability to withstand heat might be impaired by this condition. You can feel uncomfortable when you are warm and may perspire a lot. Your skin will feel warm and moist to the touch. (15)
Hair loss is another symptom associated with thyroid dysfunction. The hair may initially be thinner, fine and brittle, progressively hair loss will be seen over the entire scalp. (16)
There are other symptoms associated with hyperthyroidism which is caused by graves disease. This autoimmune condition results in excess production of thyroid hormones and is the most common cause of an overactive thyroid. It affects about one in two hundred people in the US. (17)
In addition to the previous symptoms, people with graves disease can experience problems with their eyes. They might have double vision, eye pain and light sensitivity. It can also cause the eyelids to retract and make the eyes bulge. Although rare, this condition could lead to loss of vision. (18)
Hyperthyroidism in Pregnancy
During a normal pregnancy some of the symptoms of an overactive thyroid might be present. These include issues dealing with heat, fast heart rate and tiredness.
However, if you are pregnant and also feel: that your heartbeat is irregular, you have shaky hands and either lose weight or don’t gain normal pregnancy weight you might have hyperthyroidism.
This could lead to miscarriage, low birth weight or premature birth. Preeclampsia (dangerous rise in blood pressure) or a sudden worsening of symptoms are signs for alarm.
Hyperthyroidism during pregnancy can be monitored and treated to give you a healthy pregnancy and protect your baby. (19)
There are no stages for hyperthyroidism however diagnosis can be based around measuring hormone levels.
There are three hormones that are measured if hyperthyroidism is suspected.
These are thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH).
When the thyroid is overactive, levels of T3 and T4 will be high while levels of TSH will be low.
Further tests can be done to check for graves disease. High levels of antibodies called thyrotropin receptors (TRAbs) can indicate this condition. (20)
There is no one treatment suits all solution for this condition. Factors like age, the severity of the condition, any other medical issues you have and your own preference will be taken into account.
Treatments available include:
This medication blocks the capability of the thyroid gland to produce new hormones. It can help control and manage the condition without leaving any lasting damage to the thyroid. In the case of graves disease, it can send the condition into remission in up to 30 percent of cases.
These drugs may also be used prior to other treatments. (21)
Cells in the thyroid gland need iodine to make hormones, consequently they will use any iodine they can get hold of. The fact the medication is radioactive destroys the cells which take it up from the bloodstream.
Radioactive iodine is taken once, in tablet form, and any excess is expelled from the body over time. Levels of thyroid hormones might return to normal and any nodules will shrink.
This procedure can be administered again if not successful on the first occasion. Thyroid hormone supplements may be needed daily following treatment. (22)
Permanent removal of all or part of the thyroid gland can resolve this condition. Thyroid hormone supplementation would be required daily following surgery because you no longer have the ability to make them. (23)
These drugs barricade the actions of thyroid hormones on the body and resolve associated symptoms. They do not alter the levels of thyroid hormones but can make you feel better.
These drugs may be prescribed alongside other treatments. (24)
What is hyperthyroidism? Hyperthyroidism, or overactive thyroid, happens when the thyroid gland produces too much of a hormone called thyroxine.
What are the signs of hyperthyroidism? When your thyroid is overactive you may feel anxious and restless. Your heart beat might be rapid or irregular and you can have palpitations. Dealing with heat will not be easy and you could sweat more than is normal for you. Unexplained weight loss despite an increased appetite is also a common sign of this condition.
How do you develop hyperthyroidism? The most common cause of excessive thyroid hormone production is graves disease, which often runs in families.
How are you diagnosed for hyperthyroidism? Diagnosis is usually made following a measurement of thyroid hormones in your blood.
What is the best treatment for hyperthyroidism? Following diagnosis your doctor will discuss your treatment options with you. They include drugs and/or surgery.
What are the long term complications of hyperthyroidism? If untreated an overactive thyroid can cause heart diseases or osteoporosis. On rare occasions a “thyroid storm” can happen, possibly triggered by medications containing iodine. This is a life threatening medical emergency. (25)
Is hyperthyroidism considered a disability? This condition is not considered a disability as such, however, you could qualify for benefits depending on circumstances.
Is there a cure for hyperthyroidism? Medication can manage this condition and surgery can be carried out to remove the thyroid. However, the body needs thyroid hormones to function so daily supplements might need to be taken.
Is hyperthyroidism life threatening? When left untreated, hyperthyroidism can be life threatening.
Too many thyroid hormones released by an overactive thyroid gland results in hyperthyroidism.
The symptoms are many, varied and affect people to different degrees and in contrasting ways.
However, this condition can be diagnosed and successfully treated with medication or surgery, although this may mean taking thyroid hormone supplements indefinitely.