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

Table 3.4 Symptoms suggestive of hypothyroidism

Overproduction of thyroid hormones – hyperthyroidism – is caused by an overactive thyroid. The state of being hyperthyroid, called thyrotoxicosis, is sometimes easier to spot than hypothyroidism, partly because there may be rather dramatic mental and physical effects. However, symptoms are not always obvious, but may just creep up on you. It may only be when someone else comments on how you have changed or when your doctor notices some signs that the condition is diagnosed.

Whereas an underactive thyroid slows your body down, an overactive one speeds it up, causing your metabolism to race uncontrollably. As Jan, who has Graves’ disease, the most common cause of hyperthyroidism, describes it:

I’d had a lot of trouble in my marriage and a lot of stress generally after I left. The first thing I noticed was that I was full of energy. I couldn’t sit still, I had to be working, working out, cooking or doing something with the kids all the time. I started to drink to try and slow myself down. As time went on, I couldn’t sit down long enough to think and I became totally exhausted. My muscles started to waste away, even though I was exercising so much. My periods stopped. I had bouts of breathlessness, which were diagnosed as asthma. I couldn’t think straight, my mind was so overactive. I felt as if my head was full of twittering sparrows and I had what I can only describe as an ‘electrical buzzing’ in my head.

As Jan’s account illustrates, when the thyroid becomes overactive, the body burns energy at a tremendous rate. If you are affected, you can eat like an elephant without putting on weight; in fact, more often than not, you will lose pounds instead.

As the gland continues to step up production, you may feel constantly hot and sweaty, and find yourself stripping off and throwing windows open, even on cold days. You may also notice a change in bowel habits – needing to go more often and sometimes having diarrhoea, a symptom so common that it’s not unusual for hyperthyroidism to be first diagnosed at a gastroenterology clinic. Some of those affected experience a raging thirst and pass large amounts of urine, similar to that seen in people with undiagnosed diabetes.

Anyone who has been around someone with an overactive thyroid can’t fail to notice their boundless ‘get up and go’. Sufferers pace like caged lions, talking 19 to the dozen, yet are unable to muster any concentration. Their energy never flags for a second, even at bedtime. Recalls Louise, 38:

I couldn’t settle for the jumble of racing thoughts that were flying around my brain. My sex drive increased, too – I wouldn’t leave my husband alone.

Louise’s experience echoes that of many others, and is thought to occur because of the increased turnover of male-type sex hormones – androgens – which control the libido and are converted into the female hormone – oestrogen – in the body.

Wildly swinging moods are a key feature of thyroid overactivity. One minute you are optimistic and on top of the world, the next you are plunged into the depths of despair. Nervousness and anxiety are also characteristic, probably as a result of increased sensitivity to the effects of the stress hormone adrenaline, which triggers the body’s ‘fight or flight’ reaction. Unfortunately, some find that when they report symptoms to their doctor, they are seen to be a cause rather than an effect of their problem. Just as people with an underactive thyroid may find themselves dismissed or treated with antidepressants, it has been known for those with hyperthyroidism to be referred for psychiatric help for manic-depression.

An overactive thyroid can affect your physical appearance. Your skin becomes thin, pink and moist; you tend to flush easily, and your palms may become red and sweaty. Your hair becomes fine and flyaway, and falls out while your nails become thin and flaky.

A number of those with Graves’ disease develop thyroid eye disease ( see Chapter 8 ) and some will also develop an infiltrating skin disorder causing the skin on the front of the shins to become lumpy, red and thickened skin in the front of the shins – a condition also known as pretibial myxoedema. These symptoms can appear years before or after the thyroid becomes overactive.

Some people with hyperthyroidism develop thyrotoxic tremor – a constant, fine trembling that is most noticeable when the hands are stretched out. This is thought to be due to an oversensitivity to adrenaline. Maria, 35, a freelance photographer, recalls that this tremor was the first thing she noticed when her thyroid became overactive:

I first became aware of the problem when I noticed that I wasn’t able to hold my camera steady. I couldn’t hold a pen straight to write either, and I started having palpitations. My heart beat so fast that, on one occasion, I was convinced that I was going to have a heart attack. I was losing weight rapidly: I went from my usual eight-and-a-half to nine stone to seven-and-a-half stone, even though I was eating like a pig. And I was irritable and bad-tempered.

Like hypothyroidism, untreated hyperthyroidism can damage the heart. The palpitations Maria describes are a common feature, caused by an overactivity of the heart muscle that causes the pulse to accelerate; this can lead to palpitations and an irregular heartbeat, called atrial fibrillation ( see Chapter 10 ), especially in older women. Breathlessness is another common symptom and this, too, is sometimes misdiagnosed as asthma or bronchitis. The slightest exertion can bring on an attack.

An overactive thyroid can also disturb your body’s calcium balance, accelerating the natural rate of bone loss. Bone is a living tissue that is constantly being built up and broken down. Thyroid overactivity speeds up the breakdown part of this natural cycle. This, in turn, can lead to thinning of the bones (osteopenia) and an increased risk of osteoporosis when you are older.

Weakness as a result of wasting of the muscles is another problem for about half of all hyperthyroid sufferers. As Sarah remembers:

I am a marathon runner, but I just couldn’t run at all. If I got down on the floor, someone had to help me up.

Very rarely – and particularly in those who are Asian – people with an overactive thyroid can experience periodic paralysis, attacks of profound muscle weakness or paralysis brought on by eating sugary or starchy foods. This is due to a disturbance of the body’s ability to maintain a constant concentration of potassium in the blood.