Saturday, July 14, 2012

What Is Graves' Disease? What Causes Graves' Disease?

Graves' disease is an autoimmune disease in which the patient's own immune system attacks the thyroid gland, causing it to produce too much thyroxine. Thyroxine (T4) is a hormone produced by the thyroid gland that has four iodine molecules attached to its molecular structure. T4, as well as other thyroid hormones help regulate growth and control metabolism in the body.

Graves' disease is a form of hyperthyroidism. When thyroxine levels are high the patient's metabolic rate increases; this can have an effect on their physical appearance as well as moods.

Although Graves' disease may develop at any age in both women and men, it more commonly affects women aged 20 years or more. Currently, there are no medications or treatment to stop the patient's immune system from attacking their thyroid gland. However, treatments do exist which can ease the symptoms and bring down the production of thyroxine.

What are the symptoms of Graves' disease?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor notice. For example, pain may be a symptom while a rash may be a sign.
  • Anxiety
  • Moodiness and irritability
  • Insomnia
  • Tiredness
  • Arrhythmia (irregular heart beat)
  • Tachycardia (accelerated heart beat)
  • Tremor in the hands and fingers
  • Sensitivity to heat
  • Weight loss, even though the patient eats properly
  • Brittle hair
  • Goiter (thyroid gland is enlarged)
  • Menstrual cycle changes
  • Bowel movements are more frequent

Graves' ophthalmopathy (exophthalmos) symptoms

Patients commonly have mild symptoms of Graves' ophthalmopathy.

Exophthalmos means bulging or protruding eyes. Graves' ophthalmopathy includes bulging eyes. The tissues and muscles behind the eyes become inflamed (they swell). The eye socket (orbit) is hard and inflexible and cannot accommodate the larger eyeball, so the eye bulges out. Graves' ophthalmopathy is much more common among smokers with Graves' disease compared to non-smokers with Graves' disease.

In more severe cases the eyelids cannot close properly, especially when the patient is sleeping, and the eyes can become dry.

Patients with Graves' ophthalmopathy may have the following signs and symptoms:
  • Itchy eyes (some call it gritty eyes)
  • Inflamed eyes
  • Reddened eyes
  • The space between the eyelids widens
  • The eyelids and tissues around the eyes swell
  • Photophobia (sensitivity to light)
In more severe cases the following signs and symptoms are possible:
  • Corneal ulcers
  • Diplopia (double vision)
  • Restricted eye movements
  • Reduced or blurred vision

Graves' dermopathy

The patient's skin reddens and becomes inflamed (swells), usually on their shins and on the top of their feet. This is not common.

If you have the following signs or symptoms you should see a doctor immediately:
  • Swollen thyroid
  • Bulging eyes
  • Anxiety
  • Tremor (hands and fingers shake)
  • Weight loss
  • Intolerance to heat
  • Rapid or irregular heartbeat (emergency care should be sought)

What are the causes of Graves' disease?

Graves' disease is an autoimmune disease. Healthy people's immune systems attack pathogens; organisms and substances that are bad for us, such as some bacteria, viruses, parasites, cancer cells and fungi. If the person's immune system starts attacking good tissue they have an autoimmune disease - the immune system is attacking parts of the person's body that are needed for good health. Graves' disease is an example of an autoimmune disease. Experts are not sure why autoimmune diseases, such as Graves' disease occur.

Instead of destroying the thyroid gland, an antibody called thyrotropin receptor antibody (TRAb) makes the thyroid gland produce large amounts of thyroid hormone.

The thyroid gland is part of the endocrine system, and is located in the neck, below the Adam's apple. It produces hormones which help to regulate growth and the rate of chemical reactions by which the body uses energy. The thyroid gland produces thyroxine and triiodothyronine. Thyroxine affects many body systems and has a key role in regulating our body's metabolic rate - the rate at which chemical reactions occur in our body; the rate at which our bodies break things down to produce energy, and build new tissue (metabolism).

What are the risk factors for Graves' disease?

A risk factor is something which increases the likelihood of developing a condition or disease. For example, obesity significantly raises the risk of developing diabetes type 2. Therefore, obesity is a risk factor for diabetes type 2.

The following risk factors are linked to a higher probability of developing Graves' disease:
  • Genetics - people with a family history of Graves' disease are more likely to develop it themselves.
  • Gender - for every male with Graves' disease there are seven females with the disease.
  • Age - the vast majority of patients experience the onset of the disease after they are 20 years old.
  • Pregnancy
  • Mental stress
  • Smoking

What are the possible complications of Graves' disease?

Heart problems - the patient may develop tachycardia (fast heartbeat), atrial fibrillation (a heart rhythm disorder), and congestive heart failure (the heart fails to pump enough blood for the whole body's requirements). With the right kind of treatment these complications are reversible.

Brittle bones - if the patient does not receive treatment their bones will become weak and they may develop osteoporosis. When calcium and mineral levels in bones drop they become weak. Overproduction of thyroid hormone interferes with the body's ability to get calcium into bones.

Thyrotoxic crisis - this is a sudden increase in the severity of signs and symptoms. The patient may develop a fever, accelerated heartbeat, confusion and even delirium. This rare complication should be treated immediately.

How is Graves' disease diagnosed?

Physical examination - the GP (general practitioner, primary care physician) or specialist examines the patient's eyes to see whether they are bulging or irritated. The thyroid is examined to determine whether it is enlarged. The doctor will also check the patient's heart rate and blood pressure. The physician will check for signs of trembling of the hands or fingers (tremor). During the interview the patient will be asked about their symptoms, medical and family medical histories.

Blood test - these are carried out to find out what the levels of TSH (thyroid-stimulating hormone) and thyroxine are. THS is a hormone which stimulates the thyroid gland - it is produced and released by the pituitary gland. Elevated levels of TRAb, an antibody, mimics TSH, making the thyroid gland overproduce thyroxine, even when TSH levels are low. A doctor may diagnose Graves' disease if the patient has low levels of TSH and high levels of thyroxine.

Radioactive iodine uptake - iodine is needed by the human body to produce thyroxine. The doctor can determine the rate at which the thyroid gland takes up iodine by giving the patient a small amount of radioactive iodine and then measuring the level of it in the thyroid gland after a set period. If the uptake of radioactive iodine is high it means that the patient's thyroid gland is producing excessive amounts of thyroxine - this occurs in Graves' disease. In some other causes of hyperthyroidism the uptake of iodine is low.

What are the treatment options for Graves' disease?

There are no medications or treatment currently available today that can stop the patient's immune system from attacking the thyroid gland and causing Graves' disease. However, a lot can be done to ease symptoms and lower the production of thyroxine or block its action. The possible treatments include:

Beta blockers - examples include propranolol (Inderal), atenolol (Tenormin), metoprolol (Lopressor) and nadolol (Corgard). Beta blockers are generally effective medications for relieving the signs and symptoms of hyperthyroidism, such as accelerated heartbeat, anxiety and nervousness, and tremors. Beta blockers have no effect on the amount of thyroxine the gland produces, but they do have some effect on the action of the thyroid hormone. Commonly, beta blockers are prescribed alongside other forms of treatment.

Anti-thyroid drugs - examples include propylthiouracil and methimazole (Tapazole). They prevent the thyroid gland from producing excessive amounts of thyroid hormone. In most cases patients will take this kind of medication for at least one year. In some cases, after a long period of treatment, the patient goes into a long-term remission of Graves' disease - the disease goes away for a long time. Eventually, however, in the majority of cases the disease eventually comes back.

Anti-thyroid drugs are commonly used in conjunction with radioactive iodine treatment or surgery to help ease the signs and symptoms.

There is a risk of liver damage, which can sometimes be serious, and even fatal, especially with propylthiouracil. Propylthiouracil is only given to patients who cannot tolerate methimazole.

Radioactive iodine treatment - iodine is needed for the gland to produce thyroid hormone. If a patient receives radioactive iodine it soon accumulates in the thyroid gland. The radioactivity slowly destroys the overactive thyroid cells, resulting in a smaller thyroid gland, and a lower production of thyroid hormone. Some patients may eventually require thyroxine treatment to make sure blood thyroid hormone levels are normal; this is because the treatment causes thyroid activity to decline.

This treatment carries a risk of worsening Graves' ophthalmopathy symptoms. However, the side effect is usually mild and temporary. Patients with severe Graves' ophthalmopathy symptoms may not be suitable for radioactive iodine treatment.

The radioactive iodine is eventually excreted in the patient's saliva and urine.

Surgery - this involves surgically removing the thyroid gland (thyroidectomy). It may be an option for patients who cannot tolerate anti-thyroid medications, or those who do not wish to receive radioactive iodine therapy. Patients will subsequently require thyroxine treatment to make sure their blood levels of thyroid hormones are adequate.

A thyroidectomy carries the risk of damage to the vocal cords and parathyroid glands. Parathyroid glands are very small glands located next to the thyroid gland; they produce a hormone which regulates blood levels of calcium. Complications are extremely rare if the patient has a good surgeon.

Treatment for Graves' ophthalmopathy (when eyes are affected)

Dry eyes - patients with mild symptoms will most likely be prescribed artificial tears for daytime use and a lubricating gel to help keep eyes moist during sleep. The following treatments may be recommended for patients with more severe symptoms:

Drugs - these may include corticosteroids to reduce swelling behind the eyes. An example includes prednisone.

Orbital decompression surgery - the bone between the orbit (eye socket) and the sinuses is removed, giving the eyes more space so they can move back in. There is a slight risk of numbness in the lips, as well as double vision.

Eye muscle surgery - the muscle that is attached to the eyeball is cut and reattached further back, giving the patient better eye alignment and movement.

Prisms - prisms in glasses may correct double vision.

Orbital radiotherapy - the aim here is to destroy tissue behind the eyes by targeting X-rays over a course of several days. This treatment is only useful for patients with severe symptoms of Graves' ophthalmopathy who have not responded well to other therapies.

Lifestyle and home treatments for Graves' ophthalmopathy

Cool compresses - the moisture in the compresses may help alleviate symptoms.

Sunglasses - bulging eyes are more sensitive to the effects of sunlight and UV rays. Sunglasses, especially those that wrap around the sides of the patient's head will protect the eyes from too much sunlight, as well as the drying effects of wind.

Lubricating eye drops - the symptoms of gritty, dry and scratchy eyes may be alleviated with lubricating eye drops during the day, and a paraffin-based gel for sleep time.

Prop your head up in bed - if your head is slightly higher than the rest of your body while you sleep, there will be less pressure on your head, which means less pressure on your eyes. This may help reduce symptoms.

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