For years, Harry Thorn thought his sleepless nights, constant sweating and anxiety were just part of who he was.

‘I would lie awake for hours with my heart thumping in my chest, struggling to get to sleep,’ says Harry, 27, a fat-loss coach who lives with his girlfriend Ellie Trew, 27.

‘I also always felt on edge, but decided that was just my personality.’

He was also ‘hot all the time – so sweaty that at dinner parties or other social events I’d feel very self-conscious’.

In fact, he had an overactive thyroid gland. Yet Harry might have continued to be in the dark about it had it not been for a fitness test he took as part of his sports and exercise degree at university.

For the test, he had to cycle in a lab while wired up to a heartrate monitor.

‘Mine was flashing 110 beats per minute before we’d even started cycling,’ says Harry, from Guildford, Surrey.

The normal range for most healthy adults is 55 to 85 beats per minute.

Harry’s was so high his teacher came to check if the monitor was broken.

‘When he realised it wasn’t, he looked shocked and told me to go to the doctors,’ he says.

At his GP surgery, they found his resting heart rate was so high that they were concerned about the strain it was putting on his heart.

Weeks of tests – including blood pressure checks and an electrocardiogram to monitor the health of his heart – brought no answers about the cause.

Harry Thorn, a fat-loss coach, only found out he had an overactive thyroid gland after a fitness test he took as part of his sports and exercise degree at university

‘It was as a last resort, after about five appointments, that the doctor said, “well, there is one last thing we could test you for – a thyroid problem – but it’s much more common in women”,’ recalls Harry.

Sure enough, two weeks later, results of a blood test revealed Harry had hyperthyroidism, also known as an overactive thyroid.

The condition develops when the thyroid gland in the neck produces too much thyroid hormone, which regulates numerous processes in the body from heart rate to metabolism. An excess of it causes multiple other processes to speed up.

Symptoms can include a racing heart, excessive sweating, heat intolerance, anxiety, tremor, diarrhoea, insomnia and unexplained weight loss.

Because of their general nature, the symptoms can get mistaken for stress, anxiety, overwork or simply having a naturally energetic personality, says Dr Saira Hameed, a consultant endocrinologist at Imperial College Healthcare NHS Trust in London.

‘One of my patients felt so unwell with a racing heart, heat intolerance and insomnia that she went to A&E and was diagnosed with anxiety,’ she says. ‘It highlights the need to be a bit of a detective when diagnosing hormone-related illnesses.’

A red flag, she says, is if someone has ‘heat intolerance that can’t be explained by a mood disorder’.

‘That should prompt doctors to consider an overactive thyroid.’

In fact, while hyperthyroidism affects around 1 per cent of women, it affects only 0.1 per cent of men. (And hypothyroidism – the opposite problem where the body doesn’t produce enough thyroid hormone – affects around eight times more women than men.)

Harry’s overactive thyroid was caused by Graves’ disease, the most common cause of hyperthyroidism which occurs when the immune system mistakenly attacks the thyroid gland, causing it to produce excessive amounts of the hormone.

‘Autoimmune conditions, including those affecting the thyroid, are much more common in women than men,’ says Dr Hameed, who is also the author of Signals: The Inside Story of Our Hormones.

‘We don’t fully understand why, but it’s thought that female hormones such as oestrogen may make the immune system more active, while testosterone may have a protective effect.’

In theory, thyroid problems should be easier to spot in men than women, says Lyn Mynott, the founder and chief executive of the charity Thyroid UK.

‘Symptoms of hyperthyroidism such as sweating, feeling unusually hot and tiredness can be put down to the menopause in women rather than a thyroid problem,’ she says.

The challenge is that men – as was the case with Harry – sometimes delay seeking help for their symptoms.

‘Once men do seek medical advice, hyperthyroidism can sometimes be picked up more quickly because the symptoms are often easier to recognise, such as excessive sweating, feeling unusually hot, trembling, anxiety and diarrhoea,’ she adds.

And yet it’s important they do seek help because without treatment, an overactive thyroid can lead to serious complications.

‘These include severe mood disturbances, including mania; heart-rhythm problems such as atrial fibrillation; weakening of the bones leading to osteoporosis; and strain on the heart that can eventually result in heart failure,’ says Dr Hameed.

Looking back Harry says he now realises he had ‘probably been dealing with symptoms for years’.

‘During a session at the gym I had to sit down and actively calm myself down, taking deep breaths, because my heart felt painful due to palpitations.’

And he found himself constantly boiling hot, sweaty and uncomfortable. What’s more, he was always hungry.

Dr Saira Hameed, a consultant endocrinologist, says though men often delay seeking care, when they do ‘hyperthyroidism can sometimes be picked up more quickly’

Harry is now on a low maintenance dose of carbimazole, which he says means he is ‘no longer tired and wired all the time’ and his ‘concentration and focus are also a lot better’

‘I had an increased appetite which I was taking advantage of to try and gain muscle,’ he says. ‘I could eat four meals every evening – no problem – and was probably consuming 6,000 calories a day.

‘I’d convinced myself the symptoms were just who I was. I never considered there could be a medical reason behind it.’

Following his diagnosis, doctors explained that while Graves’ disease is a lifelong condition, the symptoms of an overactive thyroid can usually be controlled with treatment.

Harry was prescribed carbimazole, a medication to reduce the amount of thyroid hormone his body was producing.

He says: ‘I was told to take higher doses until my thyroid hormone levels started to come down.

‘After a month or two, my dose had increased to 45-50mg – higher than the 30-40mg generally prescribed for moderate to severe hyperthyroidism – but my body didn’t tolerate it well and I became dangerously dehydrated.

‘The doctor explained that high doses can sometimes put stress on the liver and kidneys. Luckily, the medication had already started lowering my thyroid hormone levels, so I was gradually moved on to lower doses.’

Dr Hameed explains: ‘Graves’ disease can wax and wane. In some people, the overactive thyroid lasts for around 12 to 18 months before entering a period of spontaneous remission, when thyroid hormone levels return to normal. However, this is often followed by a relapse.’

Not all cases respond to medication, and some may need treatment with radiotherapy or surgery to reduce the amount of thyroid hormones the thyroid gland produces.

Harry is now on a low maintenance dose of carbimazole.

‘I take 5mg once a week, sometimes every two weeks. I’ve tried coming off it before, but the flare-ups come back.

‘I also get symptoms if I consume too much high calorie or fatty foods, like sugary doughnuts. That will almost always guarantee a flare-up. I’m much more aware of my triggers now.’

Dr Hameed says there is no prescribed diet for those with hyperthyroidism.

‘If someone has a very fast heart rate or shaky hands, it’s sensible not to drink too much caffeine as this can make those symptoms worse,’ she says.

‘Once thyroid hormone levels are under control, there’s no need to follow any specific diet.

‘However, Harry clearly knows his own body and has found certain foods don’t agree with him, so he’s sensibly avoiding them.’

Harry says his medication has made a huge difference.

‘I’m no longer tired and wired all the time, and my concentration and focus are also a lot better. I know my triggers and I’ve got my nutrition sorted.

‘I think men can be guilty of brushing things off when it comes to their health, but if you’re constantly feeling on edge, overheating or experiencing a racing heart, it’s worth speaking to your doctor.’

Dr Hameed agrees, saying: ‘Men, don’t leave things or try to explain them away. Speak to your doctor and ask about thyroid blood tests. They are quick and easy to arrange and will identify thyroid disease if it is the cause of your symptoms.

‘We have very good treatments but it’s important we make the diagnosis as soon as possible.’

As millions of Britons prepare to head abroad for their summer holidays, one destination will attract more visitors than almost any other: the Mediterranean. 

Spanning more than 20 countries – including holiday favourites Spain, France, Italy and Greece – ‘the Med’ is famed for its sun–soaked coastlines and lifestyle that has inspired the world–renowned Mediterranean diet. 

Around 18 to 20 million will make the voyage to the region – which encompasses Southern Europe, Western Asia, and Northern Africa – and many will likely take a dip in its crystal–clear waters.

But beneath the surface, the Med is home to a range of creatures and bacteria that, when encountered, can pose serious, and in some cases deadly, risks.

Rising sea temperatures have transformed parts of the region’s ecosystem in recent years, allowing some species that thrive in warmer areas to expand into locations where they were once rarely seen.

As a result, the chances of holidaymakers encountering some of these potentially dangerous species have increased.

Experts stress there is no reason to avoid swimming in the Med, but they say being aware of the risks – and knowing how to respond if something goes wrong – could help prevent a holiday from ending in disaster.  

So, which creatures and bacteria should tourists watch out for, where are they most commonly found, and what should you do if you come into contact with them? Read on to find out.

Millions of Britons will travel to the Mediterranean for their summer holidays this year – but there could be hidden risks in the sea 

The purple sea urchin is one of the most common species of sea urchin in the Mediterranean Sea

Sea urchins

You are never likely to be far from a sea urchin in the Mediterranean. As well as being common in the sea, some species are considered a delicacy and are served in restaurants across southern Europe.

The two species most commonly found in the sea are the edible purple sea urchin and the black sea urchin.

Small, round creatures covered in dozens of sharp, needle–like spines, sea urchins are typically found clinging to rocks in shallow coastal waters, rock pools and reefs. Though they are not aggressive, sea urchins can inflict painful injuries when stepped on or picked up by unsuspecting swimmers. 

A sting usually causes immediate and intense pain, followed by swelling, redness and puncture wounds.

Spines from sea urchins can also snap off beneath the skin, where they can be difficult to remove. If left untreated, these can trigger infection, inflammation and, in some cases, damage to nearby nerves, joints or bone.

In some cases people can develop more serious symptoms, including muscle weakness, shock, paralysis and breathing difficulties, which require urgent medical attention. 

These complications can lead to death. 

Experts recommend removing spines as soon as possible, soaking the affected area in hot, soapy, water to help ease the pain, and treat with over–the–counter drugs like ibuprofen or antibiotics.

Medical advice must be sought, however, with severe symptoms such as muscle weakness, paralysis, aches and fatigue.

The Mediterranean is home to dozens of jellyfish species, but one of the most troublesome for holidaymakers is the mauve stinger

Jellyfish

The Mediterranean is home to dozens of jellyfish species, but one of the most troublesome for holidaymakers is the mauve stinger.

Officially named pelagia noctiluca, the striking pink and purple jellyfish may look harmless, but it can pack a serious punch.

Its long tentacles are covered in thousands of microscopic stinging cells that inject venom into the skin. 

A sting typically causes an immediate burning pain, followed by redness, swelling, itching, blistering and visible, bumpy welts, also known as hives.

While most people recover within a few days, the pain can sometimes linger for weeks, and severe stings may leave scarring years down the line.

More serious reactions are uncommon but can include nausea, vomiting, headaches, muscle cramps and breathing difficulties. 

Expert advice on treating jellyfish stings varies depending on the species involved, but one thing doctors agree on is that urinating on the sting is a myth and should be avoided.  

Instead, anyone stung by a mauve stinger should leave the water immediately, rinse the affected area with seawater rather than fresh water, and carefully remove any visible tentacles without rubbing the skin. 

Medical advice should be sought if symptoms are severe or fail to improve.

Originally from the Red Sea, lionfish only reached the Mediterranean around a decade ago but have spread rapidly ever since

Lionfish

Originally from the Red Sea, lionfish only reached the Mediterranean around a decade ago but have spread rapidly ever since, and are increasingly calling it their home.

Instantly recognisable, they have striking red, maroon and white zebra–like stripes, fan–shaped fins and 13 long, venomous spines along their backs. 

Adults typically grow to between 12 and 18 inches long and are commonly found around rocky reefs, seagrass beds and shipwrecks.  

While they are not aggressive towards humans, lionfish will defend themselves if disturbed or accidentally stepped on. Their venomous spines can deliver an extremely painful sting. 

The venom consists of a toxin that is similar to cobra venom, and victims usually experience intense throbbing pain, along with redness, swelling, bruising and numbness around the wound. 

Some people may also develop nausea, vomiting, headaches or dizziness.

Most stings are not life–threatening and can be treated successfully with prompt medical care. 

But severe complications can occur, including difficulty breathing, fainting and, in very rare cases, cardiovascular problems, making urgent medical attention essential.

Despite their small size and unassuming appearance, weever fish are responsible for some of the most painful venomous stings in the Mediterranean

Weever fish

Despite their small size and unassuming appearance, weever fish are responsible for some of the most painful venomous stings in the Mediterranean.

The fish, which typically measure between four and eight inches long, spend much of their time buried beneath sand in shallow coastal waters, leaving only their eyes and venomous spines exposed. 

As a result, unsuspecting swimmers often step on them by accident. 

Although they are not aggressive, weever fish will sting if disturbed. Their sharp, venom-filled spines are said to be able to pierce through a leather boot, and can cause an immediate burning pain that quickly spreads through the affected limb. 

Victims often experience swelling, redness and numbness around the wound, while some develop nausea, dizziness, headaches or fever. 

The worst of the pain usually eases within a few hours, although symptoms can persist for up to 24 hours or, in some cases, several days.

Serious complications are rare but can include infection, tissue damage and severe breathing difficulties. This may require emergency medical treatment, and can lead to death.

Experts recommend immersing the affected area in hot water – as hot as can be safely tolerated – because heat helps break down the venom and relieve pain. 

Anyone with worsening symptoms or signs of infection should seek urgent medical attention.  

Scorpionfish are rarely seen because they can camoflauge perfectly into rocky seabeds and reefs

Scorpionfish

Scorpionfish are native to the Mediterranean and feature on many restaurant menus across the region. But despite being common, they are rarely seen because they are dubbed ‘masters of disguise’. 

With their red and brown colouring, scorpionfish camouflage perfectly into rocky seabeds and reefs, making them extremely difficult to spot.

Although they are not aggressive, they carry a toxic venom in the spines along their dorsal fins – on the back – which they can use if stepped on or handled.

Stings cause severe pain, followed by swelling, which can take hold of an entire arm or leg within minutes of it happening. 

In some cases, victims may also experience nausea, vomiting, dizziness, fever or muscle weakness.

More severe reactions can include difficulty breathing, fainting, low blood pressure, irregular heart rhythms and, in very rare cases, paralysis, making medical attention essential.

Experts advise anyone stung by a scorpionfish to leave the water immediately and immerse the affected area in hot water – as hot as can be safely tolerated – for 30 to 90 minutes, as heat helps break down the venom and relieve pain. 

The wound should then be washed thoroughly with soap and clean water to reduce the risk of infection.

Despite their venomous spines, scorpionfish are safe to eat when properly prepared and cooked, and are considered a delicacy in many Mediterranean countries.

Experts have warned that rising sea temperatures are creating increasingly favourable conditions for vibrio bacteria to spread across parts of Europe

Vibrio bacteria

Unlike fish, Vibrio bacteria cannot be seen lurking beneath the waves. 

The flesh-eating bacteria thrive in warm, salty or brackish water – when freshwater and seawater mix – and experts have warned that rising sea temperatures are creating increasingly favourable conditions for it to spread across parts of Europe. 

Just this week, the European Centre for Disease Prevention and Control said the flesh-eating bug could become more common in holiday destinations including France.

Cases were also last month reported in Spain, linked to unusually warm coastal waters.

People can become infected by Vibrio – triggering an illness called vibriosis – if the bacteria enter the body through cuts, grazes or other open wounds while swimming. 

Eating raw or undercooked shellfish – particularly oysters – contaminated with the bacteria can also cause illness such as diarrhoea and vomiting.

Most infections that enter through open wounds cause redness, swelling, pain and warmth around the affected area.

But in some cases the bacteria can rapidly spread into the bloodstream, leading to life-threatening sepsis.

Experts advise avoiding seawater if you have an open wound, covering any cuts with waterproof dressings and seeking urgent medical attention if redness, swelling or pain worsens, or if symptoms such as fever, chills or low blood pressure develop.

Dr Francis Hassard, a member of Applied Microbiology International’s Clean Water Advisory Group, said the risk of being infected by Vibrio bacteria rises when seas are warmer, during heatwaves, and in places where freshwater and seawater mix.

But, he told The Sun: ‘For most healthy beachgoers, the risk of serious illness is low.

‘The people who need to be most cautious are those with open cuts, ulcers, recent tattoos or surgical wounds, and those with liver disease, diabetes or weakened immune systems.’

Infections are typically treated through rest and hydration. Diarrhoea, one of the main symptoms of infection when the bacteria is ingested from food, can cause dehydration.

Other, more severe cases may require antibiotic treatment. Anyone with prolonged symptoms should seek medical advice.