How Can You Test For Graves' Disease?

What is Graves’ disease?

Graves’ disease is an autoimmune disorder where the immune system mistakenly produces antibodies that target the thyroid. 

The thyroid is a butterfly-shaped gland in the throat, and it produces hormones such as triiodothyronine (T3) and thyroxine (T4), which are essential for growth and metabolism. However, in Graves’ disease, excess thyroid hormone is produced. 

It most commonly affects females and those between 20 and 50 years of age with a family history of the disease or an existing autoimmune disorder. 

It is the leading cause of hyperthyroidism, a condition characterized by having too much thyroid hormone. 

Why is it important to test for Graves’ disease?

There are several effective treatments for Graves’ disease. Getting an accurate diagnosis through testing will help ensure you get the most suitable treatment. 

Importance of early detection

Early detection of Graves’ disease allows treatment to begin as soon as possible to prevent worsening of symptoms. 

Major complications resulting from Graves’ disease include:

• Muscle degradation

• Bone loss

• Heart abnormalities

Energy is burned faster than it can be replenished, so the body starts to use tissues and organs as a source of fuel. 

If weight loss continues rapidly and without treatment, vital bodily processes can begin to shut down, resulting in serious illness, hospitalization, or even death. 

Diagnosis

People generally seek medical help for Graves’ disease when suffering from the following symptoms:

• Hyperthyroidism

• Weight loss and increased appetite

• Irregular heartbeat

• Enlarged thyroid gland

• Heat intolerance

• Eye abnormalities 

• Skin issues

Graves’ disease is a complex condition with multiple underlying factors. A full clinical examination, discussion of patient and family history, and specialized testing are generally required to confirm a diagnosis.

Physical examination procedure

Clinical evaluation involves an examination of the following features: 

Weight

Significant weight loss and low body mass index (BMI) despite increased appetite.

Eyes (ophthalmopathy)

Swelling of the soft tissues surrounding the eyes, asymmetry of lids, redness in the eyes, and loss of vision.

Throat

Enlarged and protruding thyroid gland.

Skin (dermopathy)

Skin pigmentation and thickening. This generally occurs on the shins and sometimes spreads to the feet, and these symptoms are only present in 2–3%¹ of cases. 

Hair

Dry, coarse hair with significant hair loss.

Heart

Abnormal rhythm and heart palpitations. 

Other

Fatigue, anxiety, muscle weakness, insomnia. 

Testing methods

There are several methods of testing that can be used to diagnose a person with Graves’ disease. 

Blood tests

Thyroid-stimulating hormone (TSH) test

This is a blood test that measures levels of circulating TSH. TSH is made in the pituitary gland and is responsible for stimulating the production of thyroid hormones T4 and T3. 

Levels are often suppressed in affected patients since the thyroid is already making too much hormone, so the pituitary gland stops the production and release of TSH. 

Thyroid hormone tests

If there is no sufficient confirmation after the TSH test, blood samples are taken to examine levels of T4 (free) and T3 (free and total) thyroid hormones. 

‘Free’ refers to the active and unbound form of the hormone, which can go into cells and affect them, whereas ‘total’ is the unbound and circulating form. 

An excess of thyroid hormones indicates the presence of hyperthyroidism. 

Thyroid antibody tests

Antibody tests are performed in cases where a clinician cannot confirm a diagnosis of Graves’ disease from symptoms or tests of TSH, T4, and T3 levels.

In affected individuals, the immune system generates thyroid-stimulating immunoglobulin (TSI) and targets cells in the thyroid gland, affecting its function. The presence of TSI in a blood test can indicate Graves’ disease. 

In addition, tracking antibody levels during treatment can help to assess a person's response.

Non-blood tests 

Imaging and scans can reveal if Graves’ disease is the cause of hyperthyroidism. 

Radioactive iodine uptake (RAIU) test

This is a form of nuclear medicine, where a minute amount of radioactive iodine is ingested as a capsule or liquid. A device called a ‘gamma probe’ is then held near the thyroid gland in the throat. 

This scan measures the quantity of iodine the thyroid is obtaining from the blood to produce its hormones. High levels of iodine uptake are an indicator of Graves’ disease. 

This test is not appropriate for anyone pregnant or breastfeeding due to radiation exposure. 

Doppler ultrasonography 

This imaging method uses ultrasound waves to detect structural abnormalities in the thyroid, such as nodes, lesions, and vascularization. 

For example, a hypervascular thyroid is a sign of Graves’ disease, which means it has a higher concentration of blood vessels compared to normal. 

This diagnostic method is non-invasive and generally considered a safe testing method. However, caution should still be taken when testing during early pregnancy. 

Additional tests such as CT scans, MRI, and ultrasound of the eye area can detect any structural damage to the eyes. 

Treatment

Treatment depends on the person’s characteristics as determined from a complete medical evaluation. 

Treatment options include: 

• Radioactive iodine (RAI): a strong dose of radioactive iodine destroys cells in the thyroid gland to decrease hormone production.

• Surgery: surgical removal of all or part of the thyroid gland. This is called a ‘thyroidectomy.’

• Medication: Anti-thyroid medication, which reduces the production of thyroid hormone. The risk of relapse² is high if the drugs are discontinued. This is generally the preferred treatment option for pregnant women when given at a low dose.

The lowdown

Graves’ disease is a complex disease that presents with many symptoms.

In combination with appropriate testing, clinical examination is essential to gain a complete picture of a person’s disease status. This enables medical professionals to prescribe the most effective treatment.