Charles Bonnet syndrome – what are the cause, signs, symptoms and treatments of Charles Bonnet syndrome?

Charles Bonnet syndrome
Charles Bonnet syndrome

In Charles Bonnet syndrome, a person whose vision has started to deteriorate sees things that aren’t real (hallucinations).

The hallucinations may be simple patterns, or detailed images of events, people or places. They’re only visual and don’t involve hearing things or any other sensations.

It’s important to be aware that hallucinations associated with Charles Bonnet syndrome are caused by failing eyesight. They’re not caused by a mental health problem or dementia.

People with Charles Bonnet syndrome are usually aware that the visions aren’t real, even if they’re vivid.

Always see your GP if you’re experiencing hallucinations so they can investigate the cause.

Types of hallucination

There are two main types of hallucination that people with Charles Bonnet syndrome tend to experience. They may see:

simple repeated patterns

complex images of people, objects or landscapes

Simple repeated patterns can take the form of grids, shapes or lines, which can appear in bright or vivid colours. The patterns may lay across or cover everything the person sees.

More complex hallucinations can involve people, places, animals and insects. Most people don’t see hallucinations of people they know or past events they’ve experienced.

The hallucinations aren’t usually unpleasant or threatening, but they may be slightly frightening when first experienced. The can sometimes occur out of the blue, and can last for a few minutes or several hours. They may be moving or static.

Who’s affected and why?

Charles Bonnet syndrome affects people who’ve lost most or all of their eyesight. It’s more likely to occur if vision loss affects both eyes.

According to the Macular Society, up to half of all people with macular degeneration – a gradual loss of central vision – may experience Charles Bonnet hallucinations at some time. It’s thought there are more than 100,000 cases in the UK.

People of any age can be affected by Charles Bonnet hallucinations, but they tend to occur later in life after a person starts to lose their sight. The hallucinations often begin when a person’s sight suddenly deteriorates.

The main cause of Charles Bonnet syndrome is thought to be vision loss and how the brain reacts to it. It’s not clear how loss of vision leads to hallucinations, but research is beginning to help us better understand the relationship between the eyes and the brain.

When a person starts to lose their sight, their brain doesn’t receive as much information as it used to. It’s thought the brain sometimes responds by filling in the gaps with fantasy patterns or images that it’s stored. These stored images are experienced as hallucinations.

What effect can hallucinations have?

Visual hallucinations are a normal response the brain has to the loss of vision.

However, as Charles Bonnet syndrome isn’t widely known, many people worry about what it means and fear they may be developing a serious mental illness or dementia.

It can also cause practical problems. People who see complex hallucinations may find it difficult to get around.

Streets and rooms may be distorted, and brickwork or fencing may appear directly in front of you, making it difficult to judge exactly where you are and whether you can walk straight ahead.

Some people can overcome this problem by having good knowledge of their surroundings.

Complex hallucinations can be unsettling. Although the visions may not be frightening, it can be disturbing to suddenly see strangers in your home or garden.

For most people, the hallucinations will improve over time, with episodes becoming shorter and less frequent. Recent evidence suggests most people will still have occasional hallucinations five years or more after they first started.

If the hallucinations do stop entirely, there’s always a chance they’ll reappear after a further decline in vision.

Diagnosing Charles Bonnet syndrome

There isn’t a specific test for Charles Bonnet syndrome. Doctors diagnose it by:

talking to the person about their symptoms

taking a detailed medical history

in some cases, carrying out tests to rule out other possible causes of hallucinations, such as Alzheimer’s disease

If a person has vision loss and they’re experiencing simple or complex hallucinations and they don’t have signs of dementia or mental illness, they probably have Charles Bonnet syndrome.

Treating Charles Bonnet syndrome

There’s currently no cure for Charles Bonnet syndrome.

Simply understanding that the hallucinations are a normal consequence of vision loss, rather than a mental health problem, can be very reassuring and help the person cope better.

No specific medication has been shown to stop hallucinations caused by Charles Bonnet syndrome. Some medications that are designed to treat epilepsyParkinson’s disease and dementia have proved effective for some people.

However, these powerful medications can have serious side effects, and are therefore only recommended for people who are severely affected and under close supervision.

Self-help measures

You could try some self-help measures to help relieve your hallucinations when you experience them. For example, when a hallucination starts, you could:

change the lighting conditions to see if it disappears – for example, if you’re in a dimly lit area, switch on more lights or move to somewhere that’s brighter; if in a brightly lit area, make it dimmer

move your eyes from left to right – do this once every second 15 times without moving your head, then pause for a few seconds and repeat; it’s worth trying this up to four or five times

stare at the image and blink rapidly or reach out to touch the vision – try this for a few seconds

move around or perform a task – for example, get up to make a cup of tea

make sure you’re well rested and are getting enough sleep at night – the hallucinations may be worse when you’re tired or stressed

Some people overcome their fear by getting to know the figures in their visions.

For example, one man with Charles Bonnet syndrome has described how when he wakes up in the morning, he says, “Right, what have you got in store for me today?” to the figures he’s seeing. This allows him to have some control over the way he feels about his visions.

Help and support

If you have Charles Bonnet syndrome, talking about your hallucinations and how they make you feel may help you cope better. You could try talking to your family, friends, GP, optician, or ophthalmologist.

Mental health professionals, such as counsellors, psychologists or psychiatrists, may also be able to help if you’re finding the hallucinations particularly upsetting.

Although Charles Bonnet syndrome isn’t a mental health condition, many mental health professionals have experience of helping people come to terms with hallucinations. Your GP should be able to refer you to your local mental health team.

Read more about counselling and psychotherapy.

There aren’t many specific support groups and forums for people affected by Charles Bonnet syndrome, but there are lots of support groups for people with vision loss.

The Macular Society runs a buddy service for people affected by Charles Bonnet syndrome, where they can put you in touch with someone who’s also experienced visual hallucinations for support and reassurance. Their helpline is available on 0300 30 30 111, Monday to Friday, 9am to 5pm.

Esme’s Umbrella, an awareness campaign for Charles Bonnet syndrome, has a website with links to information and helpful resources for both patients and healthcare professionals.

The Royal National Institute of Blind People (RNIB) also has more information and advice about Charles Bonnet syndrome.

Alkaptonuria – What is black urine disease?

Alkaptonuria - Back Urine Disease
Alkaptonuria – Back Urine Disease

Alkaptonuria, or ‘black urine disease’, is a very rare inherited disorder that prevents the body fully breaking down two protein building blocks (amino acids) called tyrosine and phenylalanine.

It results in a build-up of a chemical called homogentisic acid in the body.

This can turn urine and parts of the body a dark colour and lead to a range of problems over time.

Normally, amino acids are broken down in a series of chemical reactions. But in alkaptonuria, a substance produced along the way – homogentisic acid – cannot be broken down any further.

This is because the enzyme that normally breaks it down doesn’t work properly (enzymes are proteins that make chemical reactions happen).

One of the earliest signs of the condition is dark-stained nappies, as homogentisic acid causes urine to turn black when exposed to air for a few hours.

If this sign is missed or overlooked, the disorder may go unnoticed until adulthood, as there are usually no other noticeable symptoms until the person reaches their late 20s to early 30s.

Signs and symptoms in adults

Over the course of many years, homogentisic acid slowly builds up in tissues throughout the body.

It can build up in almost any area of the body, including the cartilage, tendons, bones, nails, ears and heart. It stains the tissues dark and causes a wide range of problems.

Joints and bones

When a person with alkaptonuria reaches their 20s or 30s, they may start to experience joint problems.

Typically, they’ll have lower back pain and stiffness followed by knee, hip and shoulder pain. These are the early symptoms of osteoarthritis.

Eventually, cartilage (a tough, flexible tissue found throughout the body) may become brittle and break, leading to joint and spinal damage. Joint replacement operations are often needed.

Ears and eyes

An obvious sign of alkaptonuria in adults is thickening and blue-black discolouration of ear cartilage. This is known as ochronosis.

The earwax may also be black or reddish-brown.

Many people develop brown or grey spots on the whites of their eyes as well.

Skin and nails

Alkaptonuria can result in discoloured sweat, which can stain clothes and cause some people to have blue or black speckled areas of skin. Nails may also turn a bluish colour.

The skin colour changes are most obvious on areas exposed to the sun and where sweat glands are found – the cheeks, forehead, armpits and genital area.

Breathing difficulties

If the bones and muscles around the lungs become stiff, it can prevent the chest expanding and lead to shortness of breath or difficulty breathing.

Heart, kidney and prostate problems

Deposits of homogentisic acid around heart valves can cause them to harden and turn brittle and black. Blood vessels can also become stiff and weaken.

This can lead to heart disease and may require heart valve replacements.

The deposits can also lead to kidney stones, bladder stones and prostate stones.

How alkaptonuria is inherited

Each cell in the body contains 23 pairs of chromosomes. These carry the genes you inherit from your parents.

One of each pair of chromosomes is inherited from each parent, which means (with the exception of the sex chromosomes) there are two copies of each gene in each cell.

The gene involved in alkaptonuria is the HGD gene. This provides instructions for making an enzyme called homogentisate oxidase, which is needed to break down homogentisic acid.

You need to inherit two copies of the faulty HGD gene (one from each parent) to develop alkaptonuria. The chances of this are slim, which is why the disease is very rare – affecting just 1 in 250,000 to 500,000 people worldwide, and only around 64 people in total in the UK.

The parents of a person with alkaptonuria will often only carry one copy of the faulty gene themselves, which means they won’t have any signs or symptoms of the condition.

How alkaptonuria is managed

Alkaptonuria is a lifelong condition – there’s currently no specific treatment or cure.

However, a medicine called nitisinone has shown some promise, and painkillers and lifestyle changes may help you cope with the symptoms.


Nitisinone is not licensed for alkaptonuria – it’s offered “off label” at the National Alkaptonuria Centre, the treatment centre for all alkaptonuria patients based at Royal Liverpool University Hospital.

Nitisinone reduces the level of homogentisic acid in the body. It’s currently an experimental treatment, but research into its effectiveness is ongoing and there have been some promising results so far.

The AKU Society has information on DevelopAKUre, a clinical trial programme for nitisinone. Register your interest for DevelopAKUre.


If the condition is diagnosed in childhood, it may be possible to slow its progression by restricting protein in the diet, as this may reduce levels of tyrosine and phenylalanine in your body.

A low-protein diet can also be useful in reducing the risk of potential side effects of nitisinone during adulthood. Your doctor or dietitian can advise you about this.


If alkaptonuria causes pain and stiffness, you may think exercise will make your symptoms worse. But regular gentle exercise can actually help by building muscle and strengthening your joints.

Exercise is also good for relieving stress, losing weight and improving your posture, all of which can ease your symptoms.

The AKU Society recommends avoiding exercise that puts additional strain on the joints, such as boxing, football and rugby, and trying gentle exercise such as yoga, swimming and pilates instead.

Your GP or a physiotherapist can help you come up with a suitable exercise plan to follow at home. It’s important to follow this plan as there’s a risk the wrong sort of exercise may damage your joints.

Pain relief

Speak to doctor about painkillers and other techniques to manage pain. You may want to try transcutaneous electrical nerve stimulation (TENS), where a machine is used to numb the nerve endings in your spinal cord and reduce pain. This treatment is usually arranged by a physiotherapist.

Read about living with pain.

Emotional support

A diagnosis of alkaptonuria can be confusing and overwhelming at first. Like many people with a long-term health condition, those who find out they have alkaptonuria may feel anxious or depressed.

But there are people you can talk to who can help. Talk to your GP if you feel you need support to cope with your illness. You could also visit the AKU Society website, a charity offering support to patients, their families and carers.


Sometimes surgery may be necessary if joints are damaged and need replacing, or if heart valves or vessels have hardened.

Read about some common procedures:


People with alkaptonuria have a normal life expectancy. However, they will usually experience severe symptoms, such as pain and loss of movement in the joints, which considerably impact on quality of life.

Working and carrying out strenuous physical activity will usually become very difficult, and eventually you may need mobility aids such as a wheelchair to get around.

Visit the AKU Society website for more information and support.

Air embolism – what are the signs and symptoms of the bends

Air embulism and the bends
Air embolism and the bends


An air or gas embolism is a bubble that becomes trapped in a blood vessel and blocks it. This can lead to many different symptoms depending on where the blockage occurs. It’s one of the leading causes of death among divers.

An air or gas embolism can happen when a scuba diver surfaces too quickly from any depth. This can cause air to escape into the blood vessels from the lungs (pulmonary barotrauma) or bubbles of nitrogen to form in the blood vessels (decompression illness, or “the bends”).

An embolism can develop in an artery or vein. When an air bubble travels along an artery, it moves through a system of blood vessels that gradually become narrower. At some point, the bubble may block a small artery and cut off the blood supply to a particular area of the body.

Bubbles in the veins travel around the body and can cause breathing difficulties when they reach the lungs.

How serious is it?

The seriousness of the blockage depends on which part of the body the affected blood vessel supplies blood to and the size of the air bubble. For example, an air embolism in:

  • the arteries to the brain can cause immediate loss of consciousness and may lead to seizures (fits) or a stroke – it can also cause confusion, dizziness and slurred speech
  • the coronary arteries (which lead to the heart) may cause a heart attack or an abnormal heart rhythm
  • a blood vessel to the lungs may cause a pulmonary embolism

These conditions are very serious and can be fatal, particularly if an air embolism is not recognised and treated promptly.

Even with treatment, some people who survive are left with permanent brain damage, although this is very rare.

Warning signs

Divers should always be carefully monitored by their colleagues and supervisors so any air or gas embolism can be immediately identified and treated.

Signs and symptoms of an air embolism can include:

  • joint or muscle pains
  • low blood pressure, which may cause dizziness
  • an irregular heartbeat
  • breathlessness and fast breathing
  • blurred vision
  • chest pain
  • strong feelings of anxiety and itching of the skin
  • a faint blue tone to the skin (cyanosis)
  • bloody froth from the mouth
  • paralysis or weakness, possibly of one or more limbs
  • seizures (fits)
  • loss of consciousness

If a scuba diver develops these symptoms within 10 to 20 minutes of surfacing, they probably have an air embolism and should be given 100% oxygen and transferred to hospital as soon as possible, preferably one with a recompression chamber.

Treating air embolisms

If a diver develops an air embolism, the only effective treatment is immediate recompression treatment in a special pressurised room called a hyperbaric chamber.

The diver should be given 100% oxygen and laid horizontally until they reach the hyperbaric chamber.

Recompression treatment involves lying in a hyperbaric chamber, usually for several hours, and breathing a mixture of gases and oxygen under pressure. The high pressure can restore normal blood flow and oxygen to the body’s tissues and reduce the size of the air bubbles in the body.

In cases of decompression sickness, the pressure forces the bubbles of nitrogen to dissolve back into the bloodstream.

After recompression, pressure is reduced gradually to allow the gases to leave the body without worsening the problem, similar to surfacing slowly from a dive. Treatment might be continued for several days depending on the severity of symptoms.

Preventing an air embolism while diving

The following advice can help reduce your risk of developing an air or gas embolism when diving.

  • Limit the depth and duration of your dives.
  • Come up to the surface slowly and always perform safety stops to allow any air in your tissues and blood vessels to escape safely. Use a dive computer or dive tables, and don’t dive again if you have broken these rules until you have had a suitable time at the surface.
  • Don’t dive with a cold, cough or chest infection.
  • Avoid rigorous exercise before, during and after a dive.
  • Make sure you’re well hydrated before diving.
  • If planning several dives, leave adequate surface intervals between dives to allow the nitrogen to leave your body.
  • After diving, wait for 24 hours before flying or going to a higher altitude.

If in doubt, contact a dive professional or doctor, who can provide further advice.

Other causes of air embolisms

Air embolisms also occur during surgery or other medical procedures, but this is rare.

In hospitals and health centres, care should be taken to prevent this. For example:

  • before injections, air should be removed from syringes and intravenous lines
  • catheters or other tubes inserted into the body should be inserted and removed using a technique that minimises the possibility of air getting into the blood vessels
  • patients should be closely monitored to help ensure air bubbles don’t form in blood vessels during surgery

Air embolisms resulting from surgery, anaesthesia or other medical procedures can be difficult to treat. Treatment is usually needed to support the heart, blood vessels and lungs.

For example, fluids may be used to treat a fall in blood pressure and oxygen may be given to reduce levels of other gases in the blood vessels

Haematuria – what are the signs and symptoms of blood in the urine. Also can I have some advice for my father!

Haematuria - signs and symptoms
Haematuria – signs and symptoms

The reason for reproducing this article now it that I would like your help.  My father has spent the last couple of weeks.  He has been suffering from Haematuria.  I would be very keen to hear the stories of people who have had blood in their urine and dealt with Haematuria.  Please do share your thoughts and stories in the comments box below this article.


Finding blood in your urine can be very frightening and must be investigated by a doctor, but it’s not usually a sign of anything life-threatening.

If you notice bright red blood in your urine, or if your urine has turned red or brown because it has blood in it, see your GP.

Sometimes, urine may contain only a small amount of blood invisible to the naked eye and is only apparent when a urine test is carried out for something else. This still needs to be investigated by your doctor, as healthy urine should not contain any detectable amounts of blood.

The medical name for blood in the urine is haematuria. If blood in the urine is obvious with the naked eye, it is called “macroscopic”, or “visible haematuria”. If the blood can only be detected with laboratory testing, it is called “microscopic”, or “non-visible”.

The blood will have come from somewhere within the urinary tract – the kidneys, bladder or the tubes that urine passes through. It is often the result of a urinary tract infection (UTI), such as cystitis.

This page outlines the most common reasons for blood in the urine, to give you an idea of what may be causing the problem. However, this guide should not be used to self-diagnose your condition, and it’s important to see your GP for a proper diagnosis.

Is there definitely blood in your urine?

Before you read on, it’s worth considering whether you have recently eaten beetroot, as this can colour the urine pink and cause unnecessary alarm. Some medicines, such as the antibiotics nitrofurantoin and rifampicin, can also turn your urine red or brown.

Check that the blood is actually coming from your urine and not your vagina (if you’re a woman) or back passage.

Common causes of blood in urine

These include:

a bladder infection (such as cystitis) – which typically also causes a burning pain when you urinate
a kidney infection – which may also cause a high temperature and pain in the side of your tummy
kidney stones – which may be painless, but can sometimes block one of the tubes coming from your kidneys and cause severe tummy pain
urethritis – inflammation of the tube that carries urine out of the body (urethra); it’s often caused by a sexually transmitted infection (STI) such as chlamydia
an enlarged prostate gland – this is a common condition in older men and nothing to do with prostate cancer; an enlarged prostate gland will press on the bladder and may also cause problems such as difficulty urinating and a frequent need to urinate
bladder cancer – this usually affects adults aged over 50 and can also cause you to urinate more often and more urgently, as well as pain when urinating
kidney cancer – this also usually affects adults aged over 50, and can cause persistent pain below your ribs and a lump in your tummy
prostate cancer – this is usually only seen in men aged over 50 and usually progresses very slowly; other symptoms can include needing to urinate more frequently and urgently, and difficulty emptying your bladder

Seeing your GP

Your GP will ask about your symptoms and carry out a physical examination to help determine the cause of the blood in your urine. For men, this may include a rectal examination and women may have a vaginal examination.

They will also arrange blood/and or urine tests to look for signs of an infection. If they think that an infection is likely, they may prescribe some antibiotics before you get your results and will refer you to a specialist if your test results later show you don’t have an infection.

In some cases, your GP may recommend keeping an eye on your symptoms to see if they get better on their own over time.

Referral to a specialist

Your GP should refer you urgently to a specialist if any of the following apply:

  • you have visible blood in your urine and no pain, and tests show there is no infection
  • you are 40 or over and keep getting UTIs and blood in your urine
  • you are 50 or over and a urine test picks up unexplained non-visible blood in your urine
  • you have a lump in your tummy (a possible tumour) that was picked up during physical examination by your doctor or during a scan
  • non-visible haematuria is picked up during a test, particularly if there is also protein found in the urine

You will be referred to a hospital urology or nephrology department, or a specialist haematuria clinic, for further tests to identify the cause of your symptoms.

These tests may include more blood and urine tests, an ultrasound scan, an X-ray and a cystoscopy. This is a procedure used to examine the inside of the bladder, using an instrument called a cystoscope.

Cerebral Palsy – the facts

Cerebral Palsy is considered a neurological disorder caused by brain injury or brain malformation that occurs while the child’s brain is under development. It may be before, during, or soon after the birth of child. As a result of brain damage it affects body movement and muscle coordination. Cerebral Palsy is neither contagious nor progressive. Although symptoms start becoming noticeable over the first few years of the life but the underlying condition does not worsen with time. The below infographic from UKS Mobility takes a quick look at the top things everyone needs to know about cerebral palsy, including symptoms and social issues affecting people with the condition.

Cerebral Palsy - the facts
Cerebral Palsy – the facts