The Thyroid Gland
by Dr Jackie Rose
Table of Contents
When I worked as a GP, I would often see patients who described themselves as tired and run-down or struggling to lose weight. I would usually do a thyroid blood test in the hope of picking up an abnormality. This felt like an ‘easy win’, being something I thought I could quite easily treat. In fact, the majority of the results were normal, and my patients’ symptoms were usually due to stress, over-work and poor diet and lack of exercise.
I later came to realise that treating thyroid disease properly is not so simple and requires regular monitoring and adjusting of dosage levels, and even with taking these precautions, many of my patients, once treated, still didn’t feel quite well. There is more to thyroid disease than a lack or excess of the thyroid hormone.
What Is the Thyroid Gland and What Is Its Function?
The thyroid gland is situated at the front and sides of the neck. It is shaped like a butterfly and lies just below the level of the Adam’s apple. If normal sized, you usually cannot see it nor feel it, as it is deep to the skin but in front of the windpipe (trachea) and stretches to both sides of the windpipe.
We all are born with a thyroid gland; it is essential for regulating our metabolism. The pituitary gland, at the base of the skull, releases hormones that stimulate the thyroid to work well and to release its own hormone, known as thyroxine. There are two forms of thyroxine, shortened to T3 and T4, but they work similarly, speeding up the action of the metabolism.
The Underactive Thyroid: Hypothyroidism
It is very common to have an underactive thyroid gland, especially around middle age and over. You might typically know this if you are becoming sensitive to cold weather. You may be putting on weight unexpectedly. Your hair, skin and nails may become dry, and your hair thinner. Your bowels may become more stubborn. You may feel depressed. Basically, everything slows down a bit. Carpal tunnel syndrome (CTS), with numbness and tingling around the thumb and adjacent fingers, can be a sign of hypothyroidism. Also, for women, the periods may become heavier. You may find out by accident if you have a cholesterol test and find it to be unexpectedly high. You may even have a thyroid blood test as part of a routine blood screen, but it is not always included.
Hashimoto’s thyroiditis may sound like a Japanese car, but it is the name given to autoimmune hypothyroid disease and is the most common cause of an underactive thyroid gland. There is often associated insulin resistance (pre-diabetes), because when thyroid levels are low, there are less insulin receptors on the cells. This will contribute to difficulties in losing weight.
The Overactive Thyroid: Thyrotoxicosis
An overactive thyroid is less common but more of a health issue, and is trickier to treat. It may start at an earlier age than hypothyroidism: for example, in young adults, especially women. Because the metabolism is sped up, they can notice that they feel too hot, sweat a lot, feel anxious, suffer from insomnia, lose weight when not dieting or have palpitations or perhaps an irregular pulse (atrial fibrillation). They may become easily breathless. Their hands may have a tremor. Their bowels may become looser. Periods may become lighter, or even cease temporarily.
Some women with autoimmune thyrotoxicosis (Graves’ disease) may develop more prominent eyes (exophthalmos) or, more rarely, a squint due to weakness of the muscles around the eyes. They should be under the care of an eye specialist, as there are treatments that can help, and without attention, there is a risk of damage to the eyes.
Autoimmune Disorders of the Thyroid
Autoimmune disorders of the thyroid are common, and they can cause both an underactive or an overactive thyroid. An autoimmune disorder is one where the body’s immune defences are too sensitive and start to damage the body’s own tissues. They can cluster in some people, so if you have a recently diagnosed autoimmune disorder, such as Hashimoto’s disease of the thyroid, then be alert to other possibilities, such as coeliac disease, type 1 diabetes, inflammatory bowel disease, vitiligo, etc.
Other Forms of Thyroiditis
Thyroiditis (inflammation of the thyroid) can happen after a viral infection, such as mumps or flu, or post-natally. The thyroid may be painful and tender. Often the gland is overactive at first, then as the inflammation reduces, the levels of hormone may swing to be on the low side before eventually usually coming back to a normal level. Medications may be needed for a few months only.
Thyroid Gland Swellings
Any swelling of the thyroid is known as a ‘goitre’. Such swellings may be subtle, or clearly visible. If the swelling is smooth and symmetrical across the neck, this is most likely to be benign, and in underdeveloped countries, the most common cause is a lack of iodine in the diet. Autoimmune disease may also cause a symmetrical goitre, and if the thyroid is overactive, this may be warm to the touch.
Of more concern is the presence of individual firm lumps within the thyroid gland. Such a swelling could be a sign of cancer, so it is important to quickly get it checked by your GP or physician. It is possible to confuse swollen lymph glands for thyroid nodules, but again, if these are present for more than a week or two, it is important to have them examined.
In some people, there may be multiple swellings within the thyroid gland. This can appear worrying but is often due to a condition called ‘multi-nodular goitre’, which is usually benign. For any thyroid swelling, even if smooth and regular, the standard advice is not to delay getting a medical check.
Optimising Thyroid Function in Pregnancy
If you are on thyroid medication, you ideally need to discuss this with your physician before you try to conceive. Some treatments for thyrotoxicosis should be stopped before pregnancy. It is especially crucial that a woman does not become pregnant soon after receiving radioactive iodine or while taking carbimazole or propylthiouracil (treatments for an overactive thyroid).
For women who are on treatment for an underactive thyroid, the dose of levothyroxine will need to be increased immediately, with medical advice, as soon as they know they are pregnant, and the blood levels need to be monitored regularly during pregnancy and the dosage adjusted further.
Women who aren’t known to have any thyroid issues should still ensure a good intake of iodine. If you are on a strict vegan diet, make sure to discuss iodine dosage with your doctor or pharmacist. Otherwise, milk, fish and strawberries are all good sources of iodine. Having sufficient iodine from the mother is important for the brain development of the baby.
Prevention of Autoimmune Thyroid Disorder
Professor Robert Lustig, the famous American paediatric endocrinologist, often says that to optimise health you should ‘feed the gut, protect the liver and support the brain’. For thyroid health, this is most appropriate.
It used to be thought that there was nothing that could be done to prevent autoimmune diseases and that they were ‘just bad luck’. Now there is gathering research to suggest that if you can protect the bowel lining and prevent a condition called ‘leaky gut’, it may help prevent or even treat some autoimmune conditions.
Going gluten-free might be helpful (although different clinicians vary in their opinion), because gluten can increase the risk of a ‘leaky gut’. Similarly, reducing cow’s milk may reduce inflammation for some people, while goats’ or sheep’s milk, as in feta cheese or Manchego, may be better tolerated. Other components of an ‘anti-inflammatory diet’, such as extra virgin olive oil, oily fish, herbs and spices, vegetables—especially those from the cabbage family—and minimised sugar or ultra-processed foods are more widely accepted as being of benefit to the gut, liver and brain. And ideally one should reduce exposure to toxins: for example, by drinking alcohol only in moderation, using organic foods when possible and choosing natural cosmetics, shampoos, etc.
Dr Mindy Pelz has written a book, Fast Like a Girl,* and has podcasts about thyroid disease on YouTube. She suggests that time-restricted eating can be helpful—for example, eating within a seven-hour window in the day (but not every day)—if you find you can easily tolerate skipping occasional meals and you are not pregnant, breastfeeding or frail. She says that too much calorie restriction can be counter-productive, as can a too-strict keto diet.
Please exercise caution, because it is easy to become overwhelmed by trying to avoid anything that could be harmful in any way. This can cause stress, which itself is not good for our health.
Treatment of an Underactive Thyroid
An underactive thyroid is usually treated with levothyroxine tablets. The dose starts low and gradually builds up, on the instruction of your doctor, in response to your blood test results and also any side effects. This means that it can take a few months for the symptoms to ease off. Because levothyroxine is replacing a hormone that is naturally present, side effects should be very low. However, if the dose gets too high, one may start to show the same symptoms as one would with an overactive thyroid (as above). Treatment is usually lifelong (unless, rarely, the hypothyroidism is due to a temporary condition). There should be annual monitoring of the blood, with more frequent testing: for instance, during pregnancy.
Because this replaces a natural hormone, prescription charges are free in the UK, and you can receive an exemption certificate from your GP. This may also allow you to access all your other prescriptions free of charge.
Insulin resistance (see above) may be helped by minimising sugar and reducing starchy carbohydrates in the diet and reducing the intake of ultra-processed foods. Occasional short fasts can be helpful too (as above) if you tolerate fasting well. These measures will help in maintaining or reaching a healthy weight. Regular exercise also has a part to play.
It is not unusual for the dose of thyroxine to be reduced after menopause. This is because oestrogen can interact with thyroxine, so less is needed when oestrogen levels drop.
Treatment of an Overactive Thyroid
Treating an overactive thyroid is more difficult. Medications, such as carbimazole, may have side-effects. In particular, the blood count is monitored, looking for a possible drop in the white blood cells. If there are signs of infection—such as a bad sore throat or high temperature or cough—the blood count will be checked again urgently.
Beta-blockers are often given to help reduce symptoms such as palpitations and anxiety, especially in the early weeks of treatment, while waiting for other medications to take effect.
Radioactive iodine may be offered, especially to older patients. This is very effective, but you would have to isolate from children or pregnant women at first, and often the end result is an underactive thyroid, requiring long-term levothyroxine. Fortunately, radioactive iodine only concentrates in the thyroid gland, so it shouldn’t damage any surrounding tissues.
Surgery is also a possibility, especially if the thyroid gland is enlarged. There are two separate small glands that are situated very close to the thyroid and must not be accidentally removed. These are called the parathyroid glands, and the hormones from these are important for bone growth and regulation.
This is a very rare complication of an overactive thyroid. The typical symptoms can suddenly become very exaggerated: for example, high blood pressure, confusion, fever and sometimes jaundice. If this happens, it is important to seek urgent medical attention.
The thyroid gland is not often discussed in the media, but disorders of the thyroid are commonplace. For an underactive thyroid, the treatment is with levothyroxine, which usually resolves the main symptoms, but there may be other unexplained symptoms that are more ill-defined and harder to get under control. Understanding of treatments that help prevent and treat autoimmune thyroid disorders is increasing.
In our last edition, Carol Adam wrote an excellent article on breast cancer. Since she wrote this article, a new service has become available in the UK.
Any woman or man aged 18 or over may now request a BRCA gene test if they have one or more Jewish grandparents (Ashkenazi or Sephardi). There does not have to be a family history of cancer to be eligible for this test. This is because the rate of this gene defect is 1:40 in Ashkenazi Jews and 1:140 in Sephardim, while in the general population, it is closer to 1:500.
Counselling is provided before and after testing because the decision to be tested is not straightforward. Having yourself tested may be valuable to your children and grandchildren. If the genes are detected, lifestyle changes, medications or surgery may reduce the risks of ever-developing cancer.
Altered BRCA genes increase the risk of breast cancer and ovarian cancer in women. In men, they increase the risk of male breast cancer and prostate cancer. In both men and women, they increase the risk of pancreatic cancer.
Dr Jackie Rose (Lewis) is co-author of ‘To Life! Healthy Jewish Food’ together with Judi Rose, daughter of the late Evelyn Rose. She also works voluntarily as co-chair of Salford Healthy Communities and as a GP/ nutritionist for Private GP Extra.