For millions of Britons it is one of the most frustrating – even distressing – health problems, yet one rarely spoken about.
Chronic itching, or pruritus, affects at least one in six adults, and for many the cause remains a mystery, leaving them unable to sleep and, at times, desperate for relief.
It may sound trivial, but experts warn that a long-term itch should never be dismissed. Scratching only worsens the problem, trapping people in an exhausting ‘itch–scratch cycle’. And in some cases it can be a warning sign of an underlying condition such as liver disease, type 2 diabetes or even cancer.
Last week, our GP columnist Dr Philippa Kaye invited readers to share their experiences of persistent itching. The response was overwhelming. Scores wrote in describing years of torment, failed treatments and misdiagnoses.
One 79-year-old man said he had endured an unbearable itch on his back for 12 years which drove him ‘bonkers’. His GP told him it would go away – but it never did.
And an 88-year-old reader described ‘four years of hell’, marked by sleepless nights and depression. ‘I have tried all sorts of potions and pills recommended by my doctor and dermatologist, but nothing has worked,’ he said. ‘My quality of life was zero, which made my family sad.’
Yet experts stress there is hope. Most itches, if diagnosed correctly, can be treated, often with simple over-the-counter creams or prescription medicines.
So, with their help, here is our ultimate guide to what could be behind that maddening itch – and how to finally get rid of it.
Chronic itching, or pruritus, affects at least one in six adults, and for many the cause remains a mystery, leaving them unable to sleep
The condition to avoid scratching at all costs
Eczema affects around 1.5 million people in the UK, with flare-ups that can make the urge to scratch almost impossible to resist.
The chronic skin condition, also known as atopic dermatitis, causes red, cracked and raw patches that can be both painful and disfiguring. In some cases it even affects the ear canal.
Scratching only makes matters worse, damaging the skin and fuelling an itch–scratch cycle that is hard to break.
Eczema is most common in childhood and is thought to be linked to an over-active immune system.
In sufferers, the skin’s natural barrier – which normally locks in water and keeps irritants out – is weaker. This allows the skin to dry and crack, letting allergens seep in. The immune system treats these as threats and releases inflammatory molecules, which in turn make nerve endings more sensitive, driving the intense itch.
‘Over-the-counter moisturising treatments, known as emollients, and steroid creams can help reduce swelling, redness and itching,’ says Dr Anshoo Sahota, consultant dermatologist at the OneWelbeck clinic.
If eczema strikes inside the ear canal, resist the temptation to use cotton buds – they cause more damage and dryness. Instead, use a few drops of olive oil or ask your GP for steroid drops.
Infection that loves to hide in moist crevices
The skin is home to countless species of fungi – tiny spores that normally live harmlessly alongside bacteria as part of the body’s natural ecosystem. But when they grow out of control, or the immune system overreacts to their presence, they can trigger itchy and sometimes painful infections – from athlete’s foot to ‘jock itch’ in the groin and ringworm.
Typical signs include a red, swollen or bumpy rash in areas where moisture collects, such as between the toes, in the groin or under the arms. Ringworm is distinctive – a red, circular rash with a raised, scaly edge.
Excess moisture encourages fungal spores to multiply, which is why they spread so easily in communal showers and locker rooms. Antibiotics or a weakened immune system can also upset the skin’s balance and allow fungi to thrive.
‘If left untreated, fungal infections can become quite painful,’ warns Dr Angela Tewari, dermatologist at The Lister Hospital in London. ‘An embarrassing itch in the groin or armpits should always be investigated.’
Mild infections often respond to over-the-counter antifungal creams. But if the problem doesn’t clear within two weeks – or if it involves the scalp, face or genitals – see a GP for prescription-strength tablets or a medicated shampoo.
Tiny parasites which burrow into your skin
Once thought of as a disease of Victorian workhouses, scabies is making a comeback in Britain.
The condition is caused by microscopic mites burrowing into the skin to lay their eggs, and spreads easily through close contact – making university students, nursery staff and care home workers especially vulnerable.
The first sign is usually an intense itch, often worse at night.
A rash can take up to eight weeks to appear, typically in the folds of the elbows, knees, buttocks and between the fingers and toes.
In some cases, faint ‘trails’ – lines under the skin where mites have burrowed – are visible.
Men may also notice raised red spots on the genitals resembling mosquito bites.
Those with weaker immune systems can develop a more severe form called crusted scabies, involving a much higher density of mites.
Because the symptoms can mimic eczema or dermatitis, scabies can be tricky to diagnose. Doctors usually rely on the pattern of itching and rash, though in uncertain cases they may scrape the skin to look for mites or eggs under a microscope.
‘Scabies is incredibly itchy – far worse than other skin conditions because the body mounts such a strong reaction,’ says Dr Sahota.
Treatment usually involves applying an anti-parasitic lotion, available from pharmacists, over the entire body and leaving it on for up to 12 hours.
A prescription pill, ivermectin, may also be used.
The process must be repeated a week later, and all clothes, bedding and towels should be washed at 50C or higher to kill any lingering mites.
The itching may persist for up to six weeks after treatment, warns Dr Sahota, but ‘as long as it’s done correctly, it will eventually go’.
Lingering virus which can re-emerge
Most people have chickenpox during their childhood. But the varicella-zoster virus which causes it can lie dormant in the body for years, only to reactivate when the immune system is weakened. This is known as shingles.
It might start as a tingling or painful feeling in the skin, alongside a headache and general feeling of being unwell. The itchy, painful rash then appears a few days later, and will affect only one side of the body.
Mild cases may clear up on their own within a month. But more severe cases may need antiviral drugs, which are most effective if given in the first 72 hours.
Rarely, it can affect the eyes – look out for a rash on the forehead, eyelid or nose – which requires an urgent referral to an ophthalmologist as it can lead to permanent vision damage.
‘The earlier you get shingles treated, the less likely you are to have lasting pain or complications,’ Dr Sahota adds.
Itch can be a sign of thyroid problems 
When the thyroid gland is underactive, this slows the turnover of skin cells and reduces oil and sweat production, leaving skin dry and itchy
Itching all over the body, combined with dry, flaky skin and weight gain, can be a sign of thyroid problems.
The thyroid – a butterfly-shaped gland in the throat – produces hormones that regulate everything from metabolism to skin health.
When the gland is underactive, a condition known as hypothyroidism, too little hormone is made. This slows the turnover of skin cells and reduces oil and sweat production, leaving skin dry and itchy.
An estimated five in 100 people in the UK are affected by hypothyroidism, mostly women.
Emollient creams may ease symptoms while hormone replacement treatment works to restore normal levels, says consultant endocrinologist Catherine Napier, of Newcastle-upon-Tyne Hospitals NHS Foundation Trust.
An overactive thyroid, or hyperthyroidism, is less common. In this case, too much hormone is produced, raising body temperature and causing excess sweating – which can make the skin feel itchy.
If the itch is accompanied by red lumps on the shins, it could point to Graves’ disease, an autoimmune condition that overstimulates the thyroid. Treatment usually involves drugs or, in some cases, surgery to remove the gland.
‘With hypothyroidism, the itch should disappear once your hormones have balanced out with treatment,’ says Ms Napier. ‘With hyperthyroidism, the anti-thyroid drugs themselves can sometimes cause itching – in which case an antihistamine may help.’
Could it be a blood sugar condition?
Diabetes is known as the silent killer because high blood sugar levels often cause few obvious symptoms.
But persistent itching – particularly around the genitals – can be a warning sign of type 2 diabetes, especially if accompanied by increased thirst or frequent urination. The itch is often thrush, an overgrowth of yeast that flourishes when glucose levels in urine are high.
‘Women are particularly at risk, so if you have frequent thrush infections alongside these other symptoms, ask your GP for a blood sugar test to rule out type 2 diabetes,’ says Douglas Twenefour of the charity Diabetes UK.
Itching on the hands and backs of the legs may also signal diabetes, as raised blood sugar can alter the skin’s ability to hold moisture, leaving it dry and irritated.
‘If you can reduce your blood sugar levels, the itching will disappear,’ Mr Twenefour adds.
Itchy palms could point to liver disease
If the liver is not functioning properly it can lead to a build-up of bile salts – tiny molecules made in the liver which digest and absorb fats in the intestines.
But for reasons which are not entirely clear, this build-up can cause intense itching
anywhere in the body, but particularly in the palms of the hands. It may get worse at night.
‘We don’t quite know why it happens but it is linked to liver disease,’ says Professor Douglas Thorburn, clinical adviser to the British Liver Trust charity.
‘If you have this, combined with a yellow tinge to your skin or eyes and fatigue, see your GP for a liver function test.’
Patients can take drugs such as cholestyramine, which stop bile salts from building up, antibiotic rifampicin and, in some cases, the antidepressant sertraline, although this is not always effective, Prof Thorburn adds.
Half of people with advanced kidney disease will also experience itching, which is thought to be caused by the build-up of toxins and waste.
An unexplained itch that could be cancer
The most common cause of an all-over itch with no obvious rash is iron deficiency – known as iron deficiency anaemia.
Iron is vital for making haemoglobin, the protein in red blood cells that carries oxygen around the body. Without enough, skin tissues may receive less oxygen, leading to dryness and irritation.
‘Whenever you see no rash but still have itchy skin, it’s worth getting a blood test from your GP,’ says Dr Sahota.
In rare cases, unexplained itching can be a warning sign of blood cancer, most often
lymphoma, which affects the lymphatic system – the network of glands and vessels that help the body to fight infection.
The deep burning or stinging sensation is thought to stem from the immune system reacting to chemicals produced by cancer cells.
Because it doesn’t usually involve a rash or scaly patches, it can easily be mistaken for eczema or psoriasis, explains Fiona Gebbie, clinical support nurse at King’s College Hospital in London.
‘The itching can get worse at night, or when the body gets hot, and is usually accompanied by these other symptoms,’ she adds.
Other red flags include night sweats, fevers, fatigue, unexplained weight loss and swellings in the armpits, neck or groin. A very rare form, cutaneous lymphoma, does directly affect the skin, causing itchy red plaques.
Symptom so bad people want to ‘chop off their arms’ 
Claire O’Brien-Dutson has lived with an agonising itch on her forearms for two years
For two years Claire O’Brien-Dutson has lived with an agonising itch on her forearms that ruins her sleep and daily life.
‘It’s like being poked with thousands of hot little pins,’ says the 48-year-old cleaning supervisor, pictured left, from Droylsden, Greater Manchester. ‘No matter how much you scratch, it comes back. Honest to God, it’s the worst thing in the world.’
Her GP was baffled, and creams and antihistamines did nothing. Then Claire discovered a Facebook group for brachioradial pruritus, a little-known condition that causes painful itching on the upper arms, forearms or neck.
Sufferers sharing their experiences have even said it makes them feel like they want to ‘chop off their arms’.
Its cause is unclear, though sun damage and nerve problems in the neck or spine are suspected.
Consultant dermatologist Dr Anshoo Sahota says: ‘It’s rare and poorly understood. Treatment is difficult, but new drugs such as nemolizumab or older options like amitriptyline may help.’