Lewy body dementia symptoms can include:

• Visual hallucinations. Seeing things that aren't there, known as hallucinations, might be one of the first symptoms of Lewy body dementia. This symptom often occurs regularly and may include seeing shapes, animals or people that aren't there. Hallucinations involving sounds, smells or touch are possible.
• Movement symptoms. Signs of Parkinson's disease may occur. These symptoms include slowed movement, rigid muscles, tremor or a shuffling walk. This can cause the person to fall.
• Poor regulation of body functions. The part of the nervous system that controls automatic functions is called the autonomic nervous system. Lewy body dementia can affect how well the autonomic nervous system controls blood pressure, heart rate, sweating and digestion. This can result in sudden drops in blood pressure upon standing, dizziness, falls, loss of bladder control and bowel issues such as constipation.
• Cognitive changes. People with Lewy body dementia might have changes in thinking that are similar to symptoms of Alzheimer's disease. These symptoms may include confusion, poor attention, visual-spatial problems and memory loss.
• Trouble with sleep. People with Lewy body dementia can have rapid eye movement, also known as REM sleep behavior disorder. This disorder causes people to physically act out their dreams while asleep. People with REM sleep behavior disorder may punch, kick, yell or scream while sleeping.
• Varying attention. Episodes of drowsiness, long periods of staring into space, long naps during the day or disorganized speech are possible.
• Depression or apathy. People with Lewy body dementia might develop depression or lose motivation.

In people with Lewy body dementia, there's a buildup of proteins known as Lewy bodies. This protein also is associated with Parkinson's disease. People who have Lewy bodies in their brains also can have the plaques and tangles associated with Alzheimer's disease.

A few factors seem to increase the risk of developing Lewy body dementia, including:

• Age. People older than 60 have a higher risk of getting the disease.
• Sex. Lewy body dementia affects more men than women.
• Family history. Those who have a family member with Lewy body dementia or Parkinson's disease are at greater risk.

Lewy body dementia is progressive. This means it gradually gets worse over time. As symptoms get worse, the disease can lead to:

• Worsening dementia.
• Aggressive behavior.
• Depression.
• Increased risk of falling and injury.
• Worsening of movement symptoms, such as tremors.
• Death, on average about 7 to 8 years after symptoms start.

People who are diagnosed with Lewy body dementia, also known as LBD, have a gradual decline in the ability to think. They also have at least two of the following:

• Varying alertness and thinking function.
• Repeated visual hallucinations.
• Movement symptoms.
• REM sleep behavior disorder, in which people act out their dreams during sleep.

Other symptoms that support a Lewy body dementia diagnosis include problems with the autonomic nervous system. When this happens, the body isn't able to regulate blood pressure, heart rate, body temperature and sweating.

Sensitivity to medicines that treat psychosis also supports a diagnosis. This is particularly true for medicines such as haloperidol (Haldol). Antipsychotic medicines aren't used for people with LBD because they can make symptoms worse.

No single test can diagnose Lewy body dementia. The diagnosis is based on your symptoms and by ruling out other conditions. You might need the following tests.

Neurological and physical exam

Your healthcare professional may check for signs of Parkinson's disease, strokes, tumors or other conditions. A neurological exam tests:

• Reflexes.
• Strength.
• Walking.
• Muscle tone.
• Eye movements.
• Balance.
• Sense of touch.

Test of mental abilities

A short form of this test, which assesses memory and thinking skills, can be done in less than 10 minutes. The test doesn't usually distinguish between Lewy body dementia and Alzheimer's disease. But the test can determine whether you have cognitive impairment. Longer tests that take several hours also help identify LBD.

Blood tests

These can rule out physical causes of changes in brain function, such as vitamin B-12 deficiency or an underactive thyroid gland.

Brain scans

Your healthcare professional might order an MRI or CT scan to look for signs of a stroke or bleeding and to rule out a tumor. Dementias are diagnosed based on medical history and physical exam, but imaging results can suggest whether someone has Alzheimer's disease or LBD.

If the diagnosis is unclear or the symptoms aren't typical, you may need other imaging tests. These imaging tests may support a diagnosis of Lewy body dementia:

• Fluorodeoxyglucose PET brain scans, which assess brain function.
• Single-photon emission computerized tomography (SPECT) or PET imaging. These tests can show reduced dopamine transporter uptake in the brain. This can help diagnose Lewy body dementia.

Sleep test

You may need a sleep test called a polysomnogram to check for REM sleep behavior disorder.

Autonomic function test

You may need a test that checks if your heart rate, blood pressure or other automatic functions are stable.

Heart test

In some countries, healthcare professionals also might order a heart test called myocardial scintigraphy. This checks the blood flow to your heart for signs that might point to Lewy body dementia. However, the test isn't used in the United States.

Emerging biomarkers

Studies are ongoing into other indicators of Lewy body dementia. Groups are studying a test that detects clumps of proteins linked to LBD called alpha-synuclein in samples of cerebrospinal fluid obtained through a spinal tap. They're also testing skin samples for alpha-synuclein in people with Lewy body dementia. These biomarkers are currently available but not yet widely used. They might eventually enable early diagnosis of Lewy body dementia before the full disease develops.

There's no cure for Lewy body dementia, also known as LBD, but many of the symptoms can improve with targeted treatments.

Medicines

These medicines can help improve Lewy body dementia symptoms.

• Cholinesterase inhibitors. These Alzheimer's disease medicines increase levels of chemical messengers in the brain, known as neurotransmitters. These chemical messengers are believed to be important for memory, thought and judgment. Medicines include rivastigmine (Exelon), donepezil (Aricept, Adlarity) and galantamine (Zunveyl). They may help improve alertness and thinking and may reduce hallucinations and other behavioral symptoms.

  Possible side effects include stomach upset, muscle cramps and urinating more often. Cholinesterase inhibitors also can increase the risk of certain cardiac arrhythmias.

  In some people with moderate or severe dementia, an N-methyl-d-aspartate (NMDA) receptor antagonist called memantine (Namenda) might be added to the cholinesterase inhibitor.

• Parkinson's disease medicine. The combination medicine carbidopa-levodopa (Sinemet, Duopa, others) can help reduce rigid muscles and slow movement. However, this medicine also can increase confusion, hallucinations and delusions.
• Medicines to treat other symptoms. Your healthcare professional might prescribe medicines to treat other symptoms, such as trouble sleeping or movement symptoms.

Certain medicines can worsen memory. Don't take sleep aids that contain diphenhydramine (Advil PM, Aleve PM) or medicines that treat urinary urgency, such as oxybutynin (Oxytrol).

Limit sedatives and sleeping medicines. Talk to a healthcare professional about whether any of the medicines you take might make your memory worse.

Antipsychotic medicines can cause very bad confusion, movement symptoms, sedation and sometimes death in people with LBD. Very rarely, certain second-generation antipsychotics, such as quetiapine (Seroquel) or clozapine (Clozaril, Versacloz) might be prescribed for a short time at a low dose. But they're offered only if the benefits outweigh the risks.

Therapies

Because antipsychotic medicines can worsen LBD symptoms, it might be helpful to first try other approaches, such as:

• Tolerate the behavior. Some people with Lewy body dementia aren't distressed by hallucinations. If this is true, the side effects of medicines to treat them might be worse than the hallucinations themselves.
• Modify the environment. Reducing clutter and noise can make it easier for someone with dementia to function. Caregivers' responses also sometimes worsen behavior. Avoid correcting and quizzing a person with dementia. Offer reassurance and validation of his or her concerns.
• Create daily routines and keep tasks simple. Break tasks into easier steps and focus on successes, not failures. Structure and routine during the day can be less confusing.

Symptoms and how quickly they worsen are different for everyone with Lewy body dementia. Caregivers and spouses of people with Lewy body dementia, known as care partners, may need to adapt the following tips:

• Speak clearly and simply. Maintain eye contact and speak slowly in simple sentences. Don't rush the response. Present only one idea or instruction at a time. Use gestures and cues, such as pointing to objects.
• Encourage exercise. Exercise improves physical function, behavior and depression. Some research shows exercise might slow cognitive decline in people with dementia.
• Provide mind stimulation. Playing games, completing crossword puzzles and doing other activities that involve thinking might help slow mental decline in people with dementia. Encourage artistic and creative activities, such as painting, singing or making music.
• Create opportunities for social activity. Talk to friends. Participate in religious services.
• Establish bedtime rituals. Behavior symptoms can worsen at night. Create calming bedtime rituals without the distraction of television, meal cleanup and active family members. Leave night-lights on to prevent disorientation.

Limit caffeine during the day. Discourage daytime napping and offer activities to stay active during the day. This might help prevent nighttime restlessness.

Frustration and anxiety can worsen dementia symptoms. To promote relaxation, consider:

• Music therapy, which involves listening to soothing music.
• Pet therapy, which involves the use of animals to improve moods and behaviors in people with dementia.
• Aromatherapy, which uses fragrant plant oils.
• Massage therapy.

People with Lewy body dementia often have a mixture of emotions. The person may feel confused, frustrated, angry or afraid. They may not be certain about the future and may feel grief and depression. Offer support by listening. Provide assurance that the person can still enjoy life. Be positive and do your best to help the person retain dignity and self-respect.

If you're a caregiver or care partner for someone with Lewy body dementia, watch the person closely. Make sure the person doesn't fall, lose consciousness or have a bad reaction to medicines. Provide reassurance during times of confusion, delusions or hallucinations.

Looking after yourself

Caring for a person with Lewy body dementia can be exhausting physically and emotionally. You may have anger, guilt, frustration, discouragement, worry, grief or social isolation. Help prevent caregiver burnout by:

• Asking friends or other family members for help when you need it. Consider in-home health services to help you care for the person with Lewy body dementia.
• Exercising regularly and eating a healthy diet.
• Learning about the disease. Ask questions of healthcare professionals, social workers and others on the care team.
• Joining a support group.

Many people with Lewy body dementia and their families benefit from counseling or local support groups. Contact your local agencies on health or aging to connect with support groups, healthcare professionals, resources and referrals. They also can recommend home care agencies, supervised living facilities, a phone help line and educational seminars.

You might first discuss your symptoms with a healthcare professional who may refer you to a doctor trained in dementia. This is usually a doctor trained in brain and nervous system conditions, called a neurologist, or a doctor trained in mental health conditions, called a psychiatrist.

Ask a friend or family member to come to the appointment, if possible. This person can help you remember the information you're given and give your healthcare professional information about you. Here's some information to help you get ready for your appointment.

What you can do

Make a list of:

• Your symptoms and when they began.
• All medicines, vitamins or other supplements you take, including doses.
• Questions to ask.

What to expect from your doctor

You, your spouse, partner or close friend are likely to be asked a number of questions about:

• Changes in your memory, personality and behavior.
• Visual hallucinations.
• Your history of stroke, depression, alcohol use disorder, head trauma or other neurological disorders.