Here's everything you need to know about thyroid disease

Extreme weight fluctuations, fatigue, hair loss, irregular periods? Your body might be at war with a tiny – but mighty – gland in your neck

Gigi Hadid has candidly spoken out about her experience of having thyroid problem, Hashimoto's disease. She's not the first celebrity to talk openly about thyroid struggles either as actresses Zoe Saldana and Gina Rodriguez have also discussed how it's affected their lives.

'My metabolism actually changed like crazy this year,' Gigi recently told Elle. 'I have Hashimoto’s disease. It’s a thyroid disease. It’s now been two years since taking the medication for it, so for the (Victoria’s Secret) show I didn’t want to lose any more weight. I just want to have muscles in the right place.'

What is your thyroid?

Your thyroid can be found in front of your windpipe and is a small, butterfly-shaped gland that produces the hormones, thyroxine and triiodothyronine, to regulate your metabolism, which is how your body takes food and turns it into energy. It's really important because it's part of your endocrine system so it contributes to your mood, energy and digestion. If hormone production is unbalanced, a lot of your other body's functions will slow down, too.

Overactive thyroid

This is also known as hyperthyroidism and it occurs when your thyroid gland produces too many hormones. It's more common in women and tends to affect those between the ages of 20-40. The most common cause is when your body's immune system mistakenly attacks the thyroid but it can also be affected by certain medicine or come on because of a lump on your thyroid that can result in extra tissue producing more hormones.

Underactive thyroid

Otherwise known as hypothyroidism, this is when your thyroid gland doesn't produce enough thyroid hormones. This can result in sluggishness, weight gain and often feelings of depression. This type of thyroid disease affects 15 in 1,000 women and 1 in 1,000 men.

Thyroid problem triggers

‘For younger women, autoimmunity is the most common cause of thyroid dysfunction,’ says endocrinologist Dr Mark Vanderpump. ‘This is where your immune system develops an antibody which, instead of fighting a bug, fights you instead.’

Experts don’t know why this occurs, but it only happens if you have a genetic predisposition to making these antibodies. ‘You are born with the gene and you meet something in the environment that triggers it off,’ explains Dr Vanderpump. ‘Some believe it’s a condition caused by diet, but it could be brought on by stress, pregnancy or changing hormones.’

Research into the causes and effects of thyroid dysfunction are still misunderstood, but recent studies from the University of Cincinnati suggest that migraine sufferers are at greater risk of developing hypothyroidism, while the Erasmus Medical Center in Rotterdam found that people with an underactive thyroid have an increased risk of developing type 2 diabetes. The upshot is, if you think you might have a problem, get it checked out with a simple blood test.

Thyroid problem symptoms

The symptoms vary but can be anything from mood swings (anxiety, irritability and nervousness) to feeling tired all the time. Mood swings and difficulty sleeping are another problem you might experience, as well as hyperactivity, temperature sensitivity, weight gain or loss, muscle weakness, bladder issues, persistent thirst, itchiness, menstruation disruption and a decrease in your sex drive. Yikes.

Thyroid problem signs

So how do you know if you’ve got a serious thyroid problem, as opposed to just being massively run down?

‘We use the analogy of a car when talking about the thyroid hormones,’ says Dr Sohère Roked, a bio-identical hormone specialist and GP at London’s Omniya medical clinic. ‘When the thyroid hormones are running too high, it’s akin to pushing down hard on the accelerator,’ says Dr Roked. ‘This leads to symptoms such as diarrhoea, agitation, light or no periods, hunger, disrupted sleep, fast speech and a “hyper” mood.’ When the thyroid gland is sluggish and underactive, it’s ‘similar to pushing down on the brakes’, she adds. ‘You will feel sleepy, low in mood, have long, heavy periods, be constipated, gain weight and have a low appetite. You can also have dry skin, and the hair can become thin or fall out.’ But the first signs are often extreme energy or weight changes.

Should I get my thyroid levels tested?

When to consult your GP: If you are experiencing sleepless nights, low energy, anxiety and a loss of libido, this can be a sign of an overactive thyroid. Weight gain, muscle cramps and irregular or heavy periods indicate your thyroid may be underactive.

How thyroid function is measured: A simple blood test can check your hormone levels and thyroid function. A high level of thyroid stimulating hormone (TSH) and a low level of thyroxine (T4) in the blood could be due to an underactive thyroid, while a low level of TSH and high levels of T4 and/or triiodothyronine (T3) usually points to an overactive thyroid.

How thyroid problems are treated: Overactive thyroids are usually tackled with medication, including beta-blockers, thioamides (which inhibit hormone production), radioiodine treatments or, in some cases, surgery. GPs will normally refer patients to an endocrinologist to plan treatment for an overactive thyroid. People with underactive thyroids are normally prescribed with daily hormone-replacement tablets called levothyroxine. These replace the thyroxine hormone in the body, which underactive thyroids don’t produce enough of.

What to expect after treatment begins: To treat an underactive thyroid, you’ll initially have regular blood tests until the correct dose of medication is reached. This can take a little while to get right, and if your symptoms are mild, you may not need treatment at all.

Key points for your GP: Tell your doctor if you are pregnant or planning a pregnancy, suffering from eye problems, such as blurry vision or sensitivity to light, or experiencing side effects from medication, such as an upset stomach, headaches or chest pain.

Hashimoto's thyroiditis disease

This is also known as chronic lymphocytic thyroiditis which again sees the immune system mistakenly send antibodies that attack your thyroid. It's difficult to diagnose because the symptoms, like weight gain and fatigue, are usually fairly minor at first but it can eventually develop into you having an underactive thyroid.

Thyroid cancer

A lump or swelling in your neck could be a sign of thyroid cancer but there are other less obvious signs, too. And, a lump is more often than not benign. Women between 25-65 are at greatest risk of developing the disease so you should also keep an eye on any trouble swallowing or breathing, any front of the neck pain and any changes in your voice, such as hoarseness.

Alternative treatments for thyroid problems

While experts are sceptical about the impact lifestyle changes can have, many sufferers experiment with alternative treatments. Research suggests that women between 15 and 30 tend to be more iodine deficient which, in some cases, can lead to hypothyroidism. ‘A cup of milk accounts for 50 per cent of the iodine you need each day or buy potassium iodide supplements,’ says Dr Vanderpump. Iodine also occurs naturally in sea vegetables, like kelp.

Some studies also indicate that cruciferous vegetables, such as kale and broccoli, can inhibit the body’s absorption of iodine. A study by Loma Linda University in California even found that women with soy in their diet were more likely to have a low-functioning thyroid. But specialists are adamant that if you are in any doubt, you need to get checked out by a GP.

Thyroid treatments

Luckily there is medication to help thyroid hormone imbalances and according to the Mayo Clinic, it's worth asking what foods you should be avoiding, or ingesting more of, to help with your treatment, as soy products and high-fibre foods can have adverse effects on those suffering from an underactive thyroid, like Gigi Hadid and Zoe Saldana.

Thankfully, thyroid disorders are fairly straightforward to treat. ‘With failing thyroids, the hormone is replaced in the form of synthetic thyroxin or levothyroxine tablets – like giving insulin to a diabetic,’ says Dr Vanderpump. ‘Hyperthyroidism can be a bit more troublesome. Individuals take a course of tablets for a year to bring hormone levels down to normal or, in extreme cases, are offered surgery to remove the gland permanently, followed by medication to treat the underactivity.’ Once a patient is on medication, they will need to remain on it for life, but there are very few side effects from the drugs.