The Healthy Thyroid: What you can do to prevent and alleviate thyroid imbalance. Patsy Westcott

was a combination of a side-effect from the antidepressants and poor skin-healing due to my thyroid problem.

      You may also develop a goitre (see page 56) or, alternatively, your thyroid may shrivel up (atrophy).

      Tired All the Time

      These physical symptoms are compounded by an almost overwhelming exhaustion, as Maggie, who developed an underactive thyroid after the birth of her first child, relates:

       I felt totally paralysed for three days. I was so weak I could barely walk around. That slowly improved, but I still felt slow – the way I imagine an old person must feel. I had no appetite, but even so, the weight piled on. On one occasion, I was actually vomiting for three days and I still put on a pound! I was freezing cold all the time and had to keep the heating turned up high. My face was puffy; I looked as though I had been crying. My head felt as if it was full of cottonwool. I couldn’t focus properly – if I looked at the TV and then tried to look at a newspaper, everything was blurred. I had noises in my ears. I slept very badly. I had pain and tingling in my hands that woke me up. I was also suffering from terrible constipation. I started losing my hair, but I just thought that was the normal hair loss that happens after pregnancy, but what was strange was that I didn’t have to shave my legs or pluck my eyebrows. I felt as if my whole appearance was changing. The smallest task seemed enormous – I had trouble just walking to the corner of the road. Things came to a head when we went for a walk with some friends we were visiting. I was dragging myself along at my usual snail’s pace, several yards behind. Being unable to keep up with the others really brought it home to me that it was more than just the after-effects of having a baby. Something was seriously wrong.

      June said, ‘I thought everyone else was going too fast. I didn’t realise it was me that was slow.’

      In some cases, the tiredness associated with an underactive thyroid is so troublesome that a number of doctors believe that ME/CFS (myalgic encephalomyopathy/chronic fatigue syndrome) and fibromyalgia (pain in the soft tissue and muscles accompanied by exhaustion) may be a result of undiagnosed hypothyroidism. In the absence of hard evidence from studies, there is much debate over this issue. In the US, Dr John Lowe, an expert in fibromyalgia, believes there is a clear link between the two conditions (Clinical Bulletin of Myofascial Therapy, 1997; see also www.thyroid.about.com). In the UK, Dr Charles Shepherd has found that hyper- and hypothyroid problems are associated with ME/CFS. Most conventional doctors tend to pooh-pooh the idea, but many current texts on the thyroid, especially those coming from America, consider the idea to have merit.

      The Senses

      An underactive thyroid can affect your senses as a result of tissue swelling. You may experience headaches, migraine or blurred vision. You may become slightly deaf or hear constant noises in the ears (tinnitus). Your voice may become deep and husky due to thickening of the vocal cords. Swelling and thickening of the tissues around the wrists and ankles can compress the nerves, causing pins-and-needles in the hands and feet or numbness, a condition known as carpal – tarsal, or carpal tunnel, syndrome. This can make it difficult to use a keyboard or perform other everyday tasks. Thickening of the neck tissue may cause snoring. Digestion may be impaired as the muscular contractions (peristalsis) that propel food through the gastrointestinal tract slow down. Sluggish bowels can cause constipation.

      Menstrual Disturbances and Subfertility

      Menstrual problems and subfertility – difficulty conceiving and/or maintaining a pregnancy – are both associated with an underactive thyroid (see Chapter 8). It may also be difficult to conceive because your sex life has ground to a halt. When doing anything is an effort, it may be impossible to summon up the energy for sex, especially if you are feeling unattractive due to various physical changes.

      If hypothyroidism is a result of pituitary malfunction, you may begin to produce milk from your breasts even though you are not lactating, a result of an abnormal production of the milk-producing hormone prolactin by the pituitary.

      Lyn, who was diagnosed with hypothyroidism after the birth of her second baby, says, ‘I was very irritable and my lack of libido didn’t help my marriage.’

      Effects on the Heart

      One of the most serious consequences of hypothyroidism is that the heart, like every other system in the body, slows down. Sluggish thyroid function causes excess LDL cholesterol to accumulate in the bloodstream, which can lead to atherosclerosis – narrowing and ‘furring’ of the arteries – causing insufficient oxygen to reach the muscles of the heart.

      Clues that your heart may be affected include shortness of breath on exertion or, sometimes, chest pain (angina). Another symptom of atherosclerosis is pain in the calf on exertion (intermittent claudication), caused by furred arteries in the leg.

      Tests may reveal a slow pulse rate (under 60 beats a minute), unusual in everyone except trained athletes, low blood pressure, unusual in everyone except the very young and/or very fit, and raised levels of ‘bad’ LDL cholesterol and other blood fats called triglycerides.

      Mental Effects, Depression and Mood Swings

      Mental sluggishness is a commonly reported effect of hypothyroidism. Your brain feels like cottonwool, and you find it difficult to pay attention, to concentrate and to remember. There may be a time lag while you try to recall events, and even familiar names or facts can be elusive – a mental state typically described as ‘feeling in a fog’.

      One of the biggest bones of contention is the relationship between thyroid problems, depression and mood swings. In a letter to the British Medical Journal (October 2000), consultant psychiatrist Martin Eales outlined his belief that faulty thyroid function – including so-called mild or subclinical thyroid problems – is a significant factor in triggering depression and the failure of some people to respond to treatment with antidepressants, and can aggravate mood swings in manic-depression (known medically as bipolar disorder). This idea receives some support from the fact that antithyroid peroxidase antibodies, associated with hypothyroidism, have been found in people with manic-depression. In rare instances, there may be more severe mental disturbances, such as paranoia (feelings of persecution). These symptoms – at one time cruelly described as ‘myxoedematous madness’ – quickly disappear once treatment to correct the underactive thyroid is begun.

      A Matter of Chemistry

      To understand these links, it is necessary to look more closely at the chemistry of the brain and some of the discoveries that have been made concerning how the brain and body ‘talk’ to each other. Depression has been found to be linked to changes in both the hypothalamus-pituitary-thyroid axis and the hypo – thalmus – pituitary – adrenal axis – two key hormonal circuits that link the brain and the body.

      A major step towards understanding depression came with the discovery that the condition is linked to a shortage of the brain chemical serotonin, sometimes called the ‘happiness hormone’. This led to the development of a new class of antidepressants called selective serotonin reuptake inhibitors (SSRIs) which, as the name suggests, selectively block serotonin receptors to cause levels of serotonin – and feelings of wellbeing – to rise. These drugs, of which Prozac is the most well known, are now considered the standard treatment for depression.

      Recently, researchers found that people who are depressed tend to have raised levels of thyroxine (T₄). At the same time, they have disturbances in their body clock causing lower daytime levels and a lower-than-normal night-time surge of thyroid-stimulating hormone, thought to be due to lack of serotonin. This is yet another example of how the brain and body communicate. Some doctors also suggest that the activity of T₃ is also reduced, although this is not as yet supported by any clear evidence.

      A number of psychiatrists, particularly in the US, have found that a T₃ plus antidepressant ‘cocktail’ helps lift depression faster