Hyperthyroidism
What is hyperthyroidism?Thyroxine is a body chemical (hormone) made by your thyroid gland. It is carried around your body in your bloodstream. It helps to keep your body's functions (your metabolism) working at the correct pace. Many cells and tissues in your body need thyroxine to keep them going correctly.
Hyperthyroidism means an overactive thyroid gland. When your thyroid gland is overactive it makes too much thyroxine. The extra thyroxine causes many of your body's functions to speed up. In contrast, if you have hypothyroidism, you make too little thyroxine; this causes many of the body's functions to slow down.
What are the symptoms of hyperthyroidism?
Being restless, nervous, emotional, irritable, sleeping poorly and being 'always on the go'.
Tremor of your hands.
Losing weight despite an increased appetite.
The sensation of having a 'thumping heart' (palpitations).
Sweating, a dislike of heat and an increased thirst.
Runny stools (diarrhoea) or needing to go to the toilet to pass stools more often than normal.
Shortness of breath.
Skin problems such as hair thinning and itch.
Menstrual changes - your periods may become very light or infrequent.
Tiredness and muscle weakness may be a feature.
A swelling of your thyroid gland (a goitre) in the neck may occur.
Possible complications
If you have untreated hyperthyroidism:
You have an increased risk of developing heart problems such as abnormal heart rhythm (atrial fibrillation), a weak heart (cardiomyopathy), angina and heart failure.
If you are pregnant, you have an increased risk of developing some pregnancy complications.
You have an increased risk of developing fragile bones (osteoporosis).
With treatment, the outlook is excellent as most of the symptoms and risks of complications go
What are the causes of hyperthyroidism?
Graves' disease
This is the most common cause. It can occur at any age but is most common in women aged 20-50 years. It can affect anyone but there is often a family history of the condition. There may also be family members with other autoimmune diseases (for example, diabetes, rheumatoid arthritis and myasthenia gravis).
Graves' disease is also an autoimmune disease. The immune system normally makes tiny proteins (antibodies) which travel in your bloodstream to attack bacteria, viruses and other germs. In autoimmune diseases, the immune system makes antibodies against tissues of your body. If you have Graves' disease, you make antibodies that attach to your thyroid gland. These stimulate your thyroid gland to make lots of thyroxine. It is thought that something triggers your immune system to make these antibodies. The trigger is not known.
Thyroid nodules
This is a less common cause of hyperthyroidism. Thyroid nodules are lumps which can develop in your thyroid gland. It is not clear why they develop. They are usually non-cancerous (benign) but contain abnormal thyroid tissue.The abnormal thyroid tissue in your thyroid nodules does not respond to the normal controlling system which ensures that you make just the right amount of thyroxine. Therefore, if you have a thyroid nodule, you may make too much thyroxine.
Sometimes only one nodule forms. This is called a toxic solitary adenoma. This most commonly occurs in people aged between 30 and 50 years.
The thyroid may become generally lumpy or nodular. This most commonly occurs in older people and is called a toxic multinodular goiter
Other causes
There are several other rare causes of hyperthyroidism. For example, some people who take the medicines amiodarone and lithium develop hyperthyroidism. There are various other rare conditions which result in excess thyroxine being made
And also there is important cause called…..thyroiditis
How is hyperthyroidism diagnosed?
, a low level of TSH means that your thyroid gland is overactive and is making too much thyroxine.Thyroxine (T4). A high level of T4 confirms hyperthyroidism.
Sometimes the results of the tests are borderline. For example, a normal T4 but with a low TSH. Other tests ar sometimes done to clarify the situation and the cause. For example, another blood test that measures T3 is sometimes helpful and an ultrasound scan of the thyroid gland or a thyroid scan may be done if you have a nodular goitre.
Also, if tests are borderline, one option is to repeat the tests a few weeks later, as sometimes borderline tests are due to another illness. Other tests may be done if a rare cause of hyperthyroidism is suspected.
In people with Graves' disease a blood test may detect specific autoantibodies which are commonly raised. Ant.trab……antitpo…….others
What are the treatments for hyperthyroidism?
The main aim of treatment of an overactive thyroid gland (hyperthyroidism) is to reduce your level of thyroxine to normal. Other problems, such as a large thyroid swelling (goitre) or associated eye problems, may also need treatment.Treatment options include the following
1.drugs…..2.surgery….3.Radiotherapy
Medicines - usually carbimazole
Antithyroid medicines can reduce the amount of thyroxine made by the overactive thyroid gland. The most common medicine used in the UK is carbimazole. Carbimazole does not affect the thyroxine which is already made and stored but reduces further production. Therefore, it may take 4-8 weeks of treatment for your thyroxine level to come down to normal. The dose of carbimazole needed to keep the thyroxine level normal varies from person to person. A high dose is usually given initially which is then reduced as your thyroxine levels come down.
Carbimazole is usually taken for 12-18 months at first. After this, in about half of cases, the condition will have settled down and the carbimazole can be stopped. If the condition flares up again some time in the future, a further course may be needed. However, in these cases an alternative treatment (for example, radioactive iodine) is often recommended..
Warning: carbimazole can, rarely, affect your white blood cells which fight infection. Whilst taking carbimazole, you should see a doctor urgently for a blood test if you develop any of the following:
A high temperature (a fever).
A sore throat.
Mouth ulcers.
An alternative medication called propylthiouracil is usually given instead of carbimazole if you are pregnant. Carbimazole is safe to take if you are breast-feeding.
Radio-iodine
This involves taking a drink, or swallowing a capsule, which contains radioactive iodine. The main use of iodine in your body is to make thyroxine. Therefore, the radioactive iodine builds up in your thyroid gland. As the radioactivity is concentrated in your thyroid gland, it destroys some thyroid tissue which reduces the amount of thyroxine that you make. The dose of radioactivity to the rest of your body is very low and is not dangerous. However, it is not suitable if you are pregnant or breast-feeding. In addition, after treatment, women should not become pregnant for at least six months and men are advised not to father children for at least four months.Following radioiodine treatment, you should avoid prolonged contact with others for a specified time. This may be for 2-4 weeks, depending on the amount of radio-iodine you receive. :
Surgery
Indications…….Treatment for eye problems
You may need to see an eye specialist if you develop the eye problems of Graves' disease. Relatively minor symptoms affect the eyes in about half of people with Graves' disease. Measures such as artificial tears, sunglasses and eye protectors whilst you sleep may be sufficient to help.
However, about 1 in 20 people with Graves' disease have severe eye changes. Treatment can then be more difficult and may include surgery, radiation treatment or steroid tablets.
. Smoking can actually make your eye problems worse.
Beta-blocker medicines
Some people are given a beta-blocker medicine (for example, propranolol, atenolol, etc) for a few weeks whilst the level of thyroxine is reduced gradually by one of the above treatments. Beta-blockers can help to reduce symptoms of tremor, the sensation of having a 'thumping heart' (palpitations), sweating, agitation and anxiety
Hypothyroidism (underactive thyroid)
Women, especially those older than age 60, are more likely to have hypothyroidism.
Symptoms
Fatigue
Increased sensitivity to cold
Constipation
Dry skin
Weight gain
Puffy face
Hoarseness
Muscle weakness
Elevated blood cholesterol level
Muscle aches, tenderness and stiffness
Pain, stiffness or swelling in your joints
Heavier than normal or irregular menstrual periods
Thinning hair
Slowed heart rate
Depression
Impaired memory
Causes
Autoimmune disease. Hashimoto's thyroiditis have the most common cause of hypothyroidism Thyroid surgery..Radiation therapy.
Medications. such lithium, which is used to treat certain psychiatric disorders..
Congenital disease..
Pituitary disorder.(secondary) because of a benign tumor of the pituitary gland..
Iodine deficiency. The trace mineral iodine — found primarily in seafood, seaweed, plants grown in iodine-rich soil and iodized salt — is essential for the production of thyroid hormones. In some parts of the world, iodine deficiency is common, but the addition of iodine to table salt has virtually eliminated this problem in the United States. Conversely, taking in too much iodine can cause hypothyroidism
Complications a large goiter can affect your appearance and may interfere with swallowing or breathing.
Heart problems..
Mental health issues. Depression may occur early in hypothyroidism and may become more severe over time..
Peripheral neuropathy. Long-term uncontrolled hypothyroidism can cause damage to your peripheral nerves —.
Myxedema. This rare, life-threatening condition is the result of long-term, undiagnosed hypothyroidism. Its signs and symptoms include intense cold intolerance and drowsiness followed by profound lethargy and unconsciousness. A myxedema coma may be triggered by sedatives, infection or other stress on your body. If you have signs or symptoms of myxedema, you need immediate emergency medical treatment.
Infertility
Central hypothyroidism occurs due to pituitary or hypothalamic dysfunction. This causes a low TSH, but the free T4 and total T3 levels are also low or, at least, in the low-normal range. Central hypothyroidism should be suspected in patients with a history of sellar or suprasellar surgery or in patients with pituitary disorders.
Non-thyroidal illness is a common cause of low TSH levels in hospitalized patients. The typical pattern of thyroid function tests in patients with non-thyroidal illness is low TSH, normal free T4 and low total T3 levels. When this pattern is seen in patients who are sick, no intervention is usually needed. The thyroid function tests can simply be repeated when the patient has recovered from the acute illness. Rarely, a patient may have actual hyperthyroidism in the context of non thyroidal illness.
Certain medications can also cause low TSH levels. The most frequent suspect is corticosteroid therapy, which is well-known to suppress TSH levels. Other medications include dopamine and dobutamine.
During pregnancy, TSH reference ranges are different than in non-pregnant individuals. Due to normal physiologic changes, TSH levels (particularly in the first trimester) tend to be low or in the low-normal range with slightly elevated free T4 index and total T3 levels. The serum free T4 measured by some one-step analog assays are inappropriately low in pregnancy and should not be measured by these assays during pregnancy.