Key Facts And Figures
Thyroid disease includes thyroid enlargement and thyroid hormone dysfunction. Thyroid enlargement may be benign, resulting in nodules or goitre, or malignant in people with thyroid cancer. Conditions causing thyroid dysfunction can be broadly divided into those that result in thyroid gland underactivity or overactivity .
Thyroid enlargement is common. About 15% of the UK population have clinically detectable goitres or thyroid nodules, and the lifetime risk of developing a thyroid nodule is around 5 to 10%. In many cases, thyroid glands harbouring malignancy are clinically indistinguishable from those that are not. Most people with a non-malignant enlarged thyroid gland and normal thyroid function need no treatment.
Hypothyroidism is a condition of thyroid hormone deficiency and is usually caused by autoimmune Hashimoto’s thyroiditis. Primary hypothyroidism refers to conditions arising from the thyroid gland rather than the pituitary gland . Hypothyroidism is found in about 2% of the UK population and in more than 5% of those over 60. Women are 5 to 10 times more likely to be affected than men. Long-term consequences of hypothyroidism include cardiovascular disease and an increase in cardiovascular risk factors, including hypercholesterolaemia.
How Is Congenital Hypothyroidism Diagnosed
In the UK, all babies are tested for congenital hypothyroidism soon after birth, using a tiny amount of blood taken from pricking their heel. If this test shows that the baby possibly has hypothyroidism, it will be recommended that he or she have further blood tests to confirm the diagnosis.
He or she will also have a special scan of the neck that allows doctors to see if the child’s thyroid gland is present and in the right place . The scan is painless and uses a special intravenous marker that is only taken up by the thyroid gland. This is extremely useful information as it allows us to tell you whether there is a chance of the condition happening in another child that a parent might have.
What Is Underactive Thyroid Disease
Underactive Thyroid Disease, famouslyknown as Hypothyroidism, is a health condition in which the thyroid gland doesn’t produce and supply sufficient thyroid hormones to your bloodstream. Conversely, hyperthyroidism is when the thyroid gland produces and supplies excess thyroid hormones.
The thyroid gland has the shape of a butterfly and is situated at the front of your throat, sitting below your Adam’s apple. It produces the thyroid hormones responsible for your body’s metabolism or how your body cells use the energy gotten from food.
The activities of the thyroid hormones influence your breathing, brain development, body temperature, heart and nervous system functions, muscle strength, weight, menstrual cycle, cholesterol levels, and many other vital activities.
In Hypothyroidism, metabolism becomes slower, preventing the body from performing at its best level. This happens because the supply of the thyroid hormones in the body is low. Research has shown that about 5% of individuals between 12 and above experience hypothyroidism.
Read Also: Apple Cider Vinegar Thyroid Nodules
Graves Disease Diagnosis And Treatment
A simple physical exam can reveal an enlarged thyroid, enlarged bulging eyes, and signs of increased metabolism, including rapid pulse and high blood pressure. Your doctor will also order blood tests to check for high levels of T4 and low levels of TSH, both of which are signs of Graves disease. A radioactive iodine uptake test might also be administered to measure how quickly your thyroid takes up iodine. A high uptake of iodine is consistent with Graves disease.
Theres no treatment to stop the immune system from attacking the thyroid gland and causing it to overproduce hormones. However, the symptoms of Graves disease can be controlled in several ways, often with a combination of treatments:
- beta-blockers to control rapid heart rate, anxiety, and sweating
- antithyroid medications to prevent your thyroid from producing excessive amounts of hormone
- radioactive iodine to destroy all or part of your thyroid
- surgery to remove your thyroid gland, a permanent option if you cant tolerate antithyroid drugs or radioactive iodine
Successful hyperthyroidism treatment usually results in hypothyroidism. Youll have to take hormone-replacement medication from that point forward. Graves disease can lead to heart problems and brittle bones if its left untreated.
Even Normal Thyroid Test Results Can Be Misleading
Should your thyroid test results indicate that youre in the normal range say 5.5 you may still have an underactive thyroid if you would have tested at 9 in your younger years. At 5.5, you may feel very tired, yet your doctor will tell you that your test results are normal.
Another reason that the tests are often inaccurate is because they only show what your thyroid hormone levels are on the day of testing. Your thyroid is a tricky organ to both diagnose and treat since its hormone levels fluctuate all the time. What you eat each day has a tremendous and immediate impact on it, and how much hormone it secretes.
Thyroid tests also dont indicate if your thyroid hormone is really entering your cells. Your thyroid may be manufacturing plenty of hormone, but your cells may have become resistant to the hormone and arent able to utilize it.
Read Also: Collagen And Thyroid
What Is The Outlook For Children With Congenital Hypothyroidism
It is difficult to predict whether any young child will grow up normally. However, screening for congenital hypothyroidism has been happening in the UK for long enough for us to know that almost all children who are diagnosed and treated from an early age will grow up normally.
However, a small proportion of children who have had severe hypothyroidism in the womb may have some difficulties later in life, like poor hearing, clumsiness or trouble with learning. These problems can be reduced if hypothyroidism is picked up early and treated as described above.
Heritability Of Thyroid Hormones
It has been recognised for some time that circulating TSH, free thyroxine and free tri-iodothyronine concentrations in euthyroid individuals have a much greater inter-individual than intra-individual variation. Andersen et al. showed that the width of the individual 95% confidence interval for all three variables was approximately half that of the entire group. As a result, although the population reference ranges for these parameters are wide, each individual appears to have their own set point within this. This has significant implications given that small changes in thyroid function, even within the population reference range, have been shown to have clinically detectable effects on phenotypes as varied as cholesterol, mood and longevity. Therefore at what point an individual started within the range is very important when one is trying to determine if an alteration in thyroid function has resulted in a clinical problem.
You May Like: Apple Cider Vinegar Thyroid
What Are Clinical Trials For Hypothyroidism
Clinical trialsand other types of clinical studiesare part of medical research and involve people like you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.
Researchers are studying many aspects of hypothyroidism, such as
- understanding how the disease progresses, its clinical presentation, and genetics
- investigating how effective and safe levothyroxine is for people with chronic kidney disease
What Causes An Overactive Thyroid
Thyroid problems can affect anyone, but are more common in women than men.
An overactive thyroid can be caused by a number of conditions:
- Graves disease. This is the most common cause. It is an autoimmune disease in which your bodys immune system mistakenly attacks your thyroid gland. Sometimes this condition runs in families.
- Thyroid nodules. These are benign lumps that grow on your thyroid. They can produce extra thyroid hormones. Read more about thyroid nodules.
- Too much iodine in your body. This can be caused by taking iodine supplements such as kelp or seaweed
- Thyroiditis . This can be caused by a virus or can happen soon after having a baby.
- Some medicines such as lithium or amiodarone can cause an overactive thyroid.
- Thyroid cancer. This is rare, but a thyroid cancer can affect the production of thyroid hormones.
From Overactive To Underactive
A person who has had hyperthyroidism should have his or her thyroid hormone levels checked on a regular basis. This is because most people who are treated for hyperthyroidism eventually develop hypothyroidism.The treatment causes the thyroid to become underactive. The symptoms include lethargy, unexpected weight gain, constipation and sensitivity to the cold. Underactivity is treated by hormone replacement with thyroxine tablets.This switch from overactive to underactive can seem like treatment simply replacing one condition with another, but underactivity is easily treated with hormone replacement without side effects, whereas untreated overactivity is a serious condition which invariably proves fatal if allowed to persist.
Risks And Causes Of Thyroid Cancer
A persons risk of developing thyroid cancer depends on many factors, including age, some non cancerous thyroid conditions and a family history of thyroid cancer.
We dont know what causes most thyroid cancers. But there are some factors that might increase your risk of developing it.
Having any of these risk factors doesnt mean that you will definitely develop thyroid cancer.
Don’t Miss: Do I Need To Fast For A Tsh Blood Test
What Are The Clinical Features Of Hypothyroidism
Hypothyroidism results in a reduction in the bodys metabolic rate. It is characterised by:
- Cold peripheries with pale and dry coarse skin
- Eczema craquelé a form of dermatitis in which there is a crazy paving splitting of the skin surface
- A yellowish hue to the skin secondary to carotenoderma
- Sparse and brittle hair, which comes out in handfuls
Thyroid Dysgenesis And Non
The TSH receptor gene encodes a transmembrane receptor present on the surface of follicular cells which mediates the effects of TSH secreted by the anterior pituitary and is critical for the development and function of the thyroid gland. It belongs to a subfamily of heptahelical G protein coupled receptors that have a common structure consisting of seven transmembrane segments, three extracellular and three intracellular loops, an extracellular amino terminal domain, and an intracytoplasmic carboxyl terminal tail . The actions of TSH on the thyrocyte occur principally by receptor mediated activation of Gs and subsequent generation of intracellular cyclic adenosine monophosphate . The human TSHR gene is located on chromosome 14q31 and the extracellular domain of the receptor is encoded by nine exons, whereas the transmembrane and intracellular portions are encoded by a single large exon.
Cartoon of the TSH receptor showing the positions of all the loss of function mutations reported to date. Missense mutations are shown in the circles, frameshift and deletion mutations are indicated by arrows, and splice site mutations are marked.
Inactivating mutations of the human TSHR are therefore associated with three phenotypes:
fully compensated TSH resistance to TSH
partially compensated TSH resistance to TSH
severe uncompensated resistance to TSH.
Recommended Reading: Do You Have To Fast For A Thyroid Test
Association Of Ctla4 With Gd
In 1995, Yanagawa et al. reported an association of GD with an allele of the CTLA4 gene, which was the first report showing allelic association of CTLA4 with any human autoimmune disorder. They found a significantly higher prevalence of the 106 mobility unit allele of the CTLA4n polymorphism in white GD patients compared with controls. Subsequently, the G allele of CTLA4A/G was also found to be associated with GD . The association of these two CTLA4 polymorphisms with GD has been reproduced by several subsequent studies in different populations, with relative risks between 1.4 and 3.2 . It is interesting to note that in the Tunisian population, GD was found to be associated with the A allele at CTLA4A/G, in contrast to the G allele in other populations . The association of GD with the promoter polymorphism CTLA4C/T is less consistent than with the CTLA4n and CTLA4A/G polymorphisms , suggesting that in white populations the minor allele at this polymorphism may be carried on a different haplotype to the disease susceptibility allele.
You May Like: What Organ System Is The Thyroid Gland In
How Doctors Treat Hypothyroidism
If Hypothyroidism is confirmed, the doctors move on to the next line of action, which is medical treatment. They treat Hypothyroidism by providing you with similar hormones to those your thyroid gland fails to produce. This replacement hormone, called Levothyroxine, is the human-made version of the fundamental thyroid hormone, T4 .
Although it is available as a soft gel capsule and liquid, it is primarily prescribed as a pill to be taken in the morning after breakfast. After 6 or 8 weeks of using the administered medicine, you will take a blood test. This will help your doctor confirm how well you respond to the treatment and verify if you need to adjust the prescription.
Every time the dosage is adjusted, you will take a blood test until your doctor finds a dose that works effectively on you. Once this happens, you will only need to repeat the blood test every six months. After some time, the blood testing will become once a year.
You can control Hypothyroidism if you adhere strictly to the doctor’s recommended dosage. Also, do not stop your medicine until you have a conversation with your doctor.
Don’t Miss: Do You Need To Fast For A Thyroid Test
How Is Thyrotoxicosis Diagnosed
The diagnosis is based on the combination of symptoms, as described above, together with abnormalities in blood tests used to examine thyroid hormone levels. To diagnose thyrotoxicosis, tests should show raised thyroid hormone levels in the blood and low, undetectable thyroid stimulating hormone . Thyroid stimulating hormone becomes suppressed in this way due to the excessive thyroxine and triiodothyronine already circulating in the body. This is sensed by the pituitary gland, which inhibits it from producing any more thyroid stimulating hormone.
If the patient is suspected of having autoimmune hyperthyroidism , an additional blood test to check for thyroid autoantibodies is helpful.
Complications Of An Underactive Thyroid
When treated, many people can successfully manage an underactive thyroid. However, if left untreated, the condition can lead to serious complications, including:
- Increased Risk of Heart Disease: Low levels of the thyroid hormone change the way the body processes fat, which results in high cholesterol. This increases the risk of atherosclerosis and angina.
- Goitre: Goitre occurs when the thyroid gland swells forming a visible lump in the throat. If the lump remains small it may result in a hoarse voice and cough. If the lump becomes large, it may affect swallowing and breathing.
- Pregnancy: If an underactive thyroid is under control prior to pregnancy, then there is little danger to the foetus. However, if left untreated during pregnancy, it increases the risk of pre-eclampsia, anaemia and birth defects.
- Myxoedema Coma: This severe form of hypothyroidism is extremely rare and occurs mainly in patients with long-standing, undiagnosed hypothyroidism. This life threatening condition causes confusion, hypothermia and drowsiness, and requires emergency treatment.
- Sleep Apnoea: Hypothyroidism can be a contributing factor to obstructive sleep apnoea. In certain cases, hypothyroidism causes changes to the upper airways, such as an enlargement of the tongue , which results in blockages to breathing at night. If you constantly feel tired and lethargic during the day despite having a full nights sleep, then try a portable home monitor to test for sleep apnoea.
Also Check: Tsh Blood Test Fasting Or Nonfasting
Symptoms Of Underactive Thyroid
The symptoms of an underactive thyroid usually develop slowly and gradually. They can be quite vague and can be caused by many other conditions. This can sometimes make it hard to diagnose. You might not get any symptoms at all.
If you do get underactive thyroid symptoms, they may include:
- putting on weight
- having less of an appetite for food
- feeling the cold
- feeling weak and tired and having no energy
- a puffy face
- losing your hair, which may become generally sparse
- a hoarse voice
- a slow heartbeat
- if youre a woman, your periods may be heavy, irregular or stop completely
Having an underactive thyroid can affect your mental health too. You may become forgetful and find it difficult to concentrate. And you might feel emotionally up and down, and become depressed.
If you have any of these symptoms, contact your GP.
With our GP services, we aim to give you an appointment the same day, subject to availability. Find out more about our GP services >
Treating An Underactive Thyroid
Treatment for an underactive thyroid involves taking daily hormone replacement tablets, called levothyroxine, to raise your thyroxine levels.
You’ll initially have regular blood tests until the correct dose of levothyroxine is reached. This can take a little while to get right.
Once you’re taking the correct dose, you’ll usually have a blood test once a year to monitor your hormone levels.
You’ll usually need treatment for the rest of your life. However, with proper treatment, you should be able to lead a normal, healthy life.
Recommended Reading: What Are The Side Effects Of Np Thyroid
What Happens Before Pregnancy
Ideally, your thyroid blood tests should be checked before you start trying for a baby, so that your thyroxine dose can be adjusted if necessary. Your GP can arrange this for you. Rarely, some patients with hypothyroidism are treated with a combination therapy of thyroxine and triiodothyronine . T3 does not cross the placenta, so treatment should be converted to thyroxine alone before pregnancy or as soon as possible after a pregnancy is confirmed.
Reducing Your Risk And Other Possible Causes
You might have heard of other possible causes of cancer. Stories about potential causes are often in the media and it isnt always clear which ideas are supported by evidence.
We havent included them here, either because there is no evidence about them or it is less clear.
A pooled analysis of thyroid cancer incidence following radiotherapy for childhood cancer LHS Veiga and others
Cancer. Principles and practice of oncology VT De Vita, S Hellman and SA RosenbergLippincott, Williams and Wilkins, 2018
The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015KF Brown and othersBritish Journal of Cancer, 2018. 118, Pages 1130-1141
Family History of Cancer and Risk of Sporadic Differentiated Thyroid Carcinoma
L Xu and others
Papillary thyroid cancer: Clinical features and prognosis
R Tuttle and others
You May Like: Atrophic Autoimmune Hypothyroidism