Thyroid disorders: 20 things experts want us all to know about this vital gland
Although very common, thyroid disorders can be tough to spot and are often misunderstood. Lisa Salmon finds out more
THYROID disorders are believed to affect around one in 20 people in the UK, yet because the symptoms – such as weight changes, depression and fatigue – can often be vague (or overlap with other conditions), it is not uncommon for thyroid disorders to go undetected for a long time.
"The only way to be sure you have a thyroid condition is with blood tests, as the symptoms can be quite vague and aren't specific," says Dr Steven Hurel, a consultant endocrinologist at London Bridge Hospital, part of HCA Healthcare UK (hcahealthcareuk.co.uk).
Here, he joins the British Thyroid Foundation (BTF; btf-thyroid.org) to outline 20 important points about the thyroid gland and thyroid disorders...
1. Where is the thyroid?
Dr Hurel explains that the butterfly-shaped thyroid gland lies at the front of the neck (just below the Adam's apple), and is part of the endocrine system (the system responsible for producing hormones).
2. What does it do?
The thyroid produces the hormones T4 (levothyroxine) and T3 (liothyronine) that regulate the body's metabolic rate as well as heart and digestive function, muscle control, brain development, mood, and bone maintenance.
3. Screening for thyroid problems
TSH (thyroid stimulating hormone) is made by the pituitary gland in the brain, and stimulates the thyroid gland to produce both hormones. Measuring TSH is used as a screening method for thyroid problems. If thyroid function fails, TSH rises – and if the thyroid stops producing enough thyroxine, then the TSH rises further and hypothyroidism (underactive thyroid) develops.
4. More common in women
Although both women and men can develop thyroid conditions, they're more common in women.
5. Family history can count
Thyroid problems often run in families, so if one of your close blood relatives has been diagnosed, you might be more likely to develop a thyroid disorder too – although this is not always the case.
6. Have you got hypothyroidism?
Hypothyroidism symptoms include fatigue, lethargy, cold intolerance, dry skin, brittle hair, weight gain, a hoarse voice, constipation, lower libido, muscle weakness, heavier periods, a puffy face and bags under the eyes, slow speech, movements and thoughts, depression, memory problems, difficulty concentrating, a slow heartbeat, slightly raised blood pressure and raised cholesterol.
7. Immune involvement
There are different types and causes for thyroid dysfunction. The BTF says autoimmune thyroid disease, where the immune system attacks the thyroid cells, is the biggest cause of hypothyroidism. The most common form is Hashimoto's thyroiditis.
8. Getting the balance right
Hypothyroidism is treated with synthetic levothyroxine. Cheryl McMullan, CEO of the BTF, says: "The correct dose of levothyroxine is one that restores good health. If you feel your dose isn't correct, make a note of each of your symptoms and discuss them with your doctor. They can advise you about tweaking your dose as a way of helping you feel better."
9. Beware grapefruit!
Grapefruit is known to increase the absorption of levothyroxine, as it increases acidity in the stomach.
10. And be careful with cough medicine
Some cough medicines containing large amounts of iodine can interfere with thyroid function too.
11. Go easy on the seaweed
The BTF says that some health foods taken in excess – for example, kelp, a type of seaweed – can cause hypothyroidism.
12. Brain malfunction may be a factor
Hypothyroidism can also be caused by a malfunction of the pituitary gland in the brain, which regulates thyroid hormones.
13. Congenital hypothyroidism can also happen
Sometimes babies are born with hypothyroidism, possibly because the thyroid hasn't developed or because it doesn't form thyroid hormones properly. This is known as congenital hypothyroidism.
14. Overactive thyroid
The thyroid gland can also become overactive, so TSH usually falls and becomes undetectable, as the body tries to stop the thyroid from working. This is hyperthyroidism, which leads to an increase in metabolism.
15. Have you got hyperthyroidism?
Hyperthyroidism symptoms can include weight loss despite an increased appetite, palpitations/a racing heart, sweating and heat intolerance, tiredness and weak muscles, irritability, shakiness, mood swings, thirst, loose bowels, thyroid eye disease (prominent eyes that feel gritty and sore, double vision), and an enlarged thyroid gland. Symptoms may be subtle and unnoticed for a long time, but they can also come on suddenly and severely.
16. Graves' disease
When hyperthyroidism is associated with thyroid antibodies in the blood, it's known as Graves' disease, an autoimmune condition where the immune system attacks the thyroid gland, which becomes overactive in response.
17. Stress can be a trigger
People with Graves' disease may have experienced major stress a year or so before their diagnosis. It's believed that for a various autoimmune conditions, people who are predisposed can develop them following exposure to a 'trigger'.
18. Treatment options
Hyperthyroidism treatment can include drugs or surgery, and Dr Hurel says: "It may be very transient and settle without the need for medication, but depending on the cause tablets may be needed or it may be necessary to remove the thyroid gland with surgery or using radioactive iodine treatment."
19. Not smoking is important
Hyperthyroidism is exacerbated by smoking, and smokers are up to eight times more likely to develop thyroid eye disease than non-smokers.
20. Enlarged thyroid
The thyroid can also be enlarged as a result of general swelling in one or more nodules. This is common and around 5-10 per cent of adults have a palpable nodule, with many more detectable on scans. An enlarged thyroid gland is known as a goitre.
However, it's always a good idea to get any swellings or lumps in the throat checked by a doctor, as they may sometimes be a sign of cancer. "While it's important to get any palpable nodule evaluated, only around 5 per cent or less are actually cancerous," explains Dr Hurel, "and even then the vast majority of these are totally treatable."