What Causes Hallucinations In The Elderly?

Aging is a beautiful, natural, not to forget inevitable process. We gain experiences and become wiser. After years of getting to know and understand ourselves and the world around us, it is quite unnerving when our knowledge is challenged in any way. Hallucinations do just that. They are reactions to unreal sensations that interfere with our understanding of reality. We begin to see or hear things we can’t seem to explain, even when awake and with our eyes closed. When adults reach 60 years and over, the incidence of hallucinations increase.

Visual hallucinations and musical hallucinations (tunes or harmonies instead of voices) are frequently reported by elderly individuals.1


Hallucinations should not be seen as a mere symptom of madness but something that is quite common even in sane persons, especially in senior citizens. They can be provoked by a host of factors including sleep, migraines, intoxication, and seizures. Certain factors, however, seem to be more potent triggers in the elderly.

Causes Of Hallucinations In The Elderly

As we age, our senses begin to weaken and we become more susceptible to nerve degeneration. These are risk factors for hallucinations.2 For instance, as people lose their sense of hearing, they may begin to hear sounds and voices that, in reality, are being fabricated by their brain. You don’t have to be completely deaf or blind, just sufficiently impaired.


1. Charles Bonnet Syndrome

Visual parts of the brain used to receiving external inputs for years get attuned to constantly processing visual information and fire nerve signals.3 When a person starts going blind and becomes deprived of these external stimuli, these areas of the brain become hyperactive and fabricate their own stimuli. They spontaneously fire visual signals, making a person “see” things that are not really there and mostly without any fade in or fade out.

Charles Bonnet hallucinations are different from psychotic hallucinations. The hallucinations don’t seem to have anything to do with you. They are aloof, don’t address you, and there is no interaction with you whatsoever. It’s like entering a 3D-movie you haven’t seen before while being a silent, ignored spectator.


The brain’s temporal lobe has been shown to be involved in Charles Bonnet hallucinations, particularly the face recognition area called the fusiform gyrus. Certain parts of the fusiform gyrus perceive eyes and teeth, which is why people in which these parts are hyperactive often see deformed faces with bulging eyes and abnormally large teeth. From geometrical shapes to figures and even cartoons – the range of hallucinations in this syndrome can be varied.

2. Dementia

Dementia is a progressive, irreversible syndrome involving memory loss, language impairment, disorientation, and personality change. According to surveys, 1 in 2 people suffering from dementia hallucinate.4


When an elderly person complains of visual hallucinations without auditory hallucinations, it is advisable to assume there is a biological basis – especially if they develop these hallucinations for the first time in their lives.5 Nerve degeneration, the primary cause of dementia, localized in different parts of the nervous system, can trigger visual hallucinations. Different types of dementia involved are:

  • Alzheimer’s Disease (AD)

Hallucinations occur in about 30% of patients with Alzheimer’s disease and have been linked to reductions in the brain neurotransmitter acetylcholine.6 Hallucinations are mostly visual, though they can involve any of the other senses as well, and occur between moderate and severe stages of disease progression. The hallucinations seem to discontinue at the end stage of AD.7 Their presence may indicate fast progression of the disease.8


One community-based study showed that delusions are more common in AD patients than hallucinations.9

  • Dementia With Lewy Bodies (DLB)

Approximately 1 in 5 people with DLB hallucinate – mostly well-formed visual hallucinations.10 One may see stationary objects move and complex scenarios of non-existent people and objects. The visual hallucinations provide an 83% reliable hint that the dementia is likely to be caused by Lewy bodies rather than any other cause like Alzheimer’s or Parkinson’s. Lewy bodies in the temporal lobe of the brain, particularly the amygdala and the parahippocampus, seem to be responsible for these hallucinations.

  • Parkinson’s Disease (PD)

About 25-40% of Parkinson’s patients experience hallucinations.11 These are mostly neutral and non-threatening and can even be amusing. A feeling of floating mid-air or feeling the presence of people and animals have been reported by people with PD.

3. Bereavement

A study involving widows and widowers in their early seventies showed that 1 in 3 people experience visual and auditory hallucinations in the first year of the demise of their spouse.12 Those in long, happy marriages were at a higher risk of seeing or hearing their deceased spouse, even having conversations with them. The hallucinations are not frightening but reassuring and comforting.


4. Life-Long Schizophrenia

About 1 in 200 people above the age of 65 has schizophrenia.13 Those who develop schizophrenia symptoms early on in life, before the age of 45, usually continue to experience those symptoms years later. Over 70% schizophrenics have hallucinations.14 The hallucinations are typically auditory and mostly negative. One may hear a running narrative of their actions, sometimes in the third person and very critical of one’s character and behavior.

5. Certain Medications

Certain medications cause visual hallucinations, more so when a person is on more than one medication.15 More medication means higher potential for drug interactions and, hence, hallucinations. Elderly individuals are more likely to receive treatment for different conditions than younger people, putting them at a higher risk of medication-related hallucinations.

Drugs used to treat hypertension, erectile dysfunction, movement disorders like Parkinson’s, mental disorders, and certain antibiotics have been implicated in visual hallucinations.

  • Vasoconstrictors and vasodilators: Drugs that constrict or dilate blood vessels can affect blood flow to the visual areas of the brain, thus, causing visual hallucinations.
    Viagra for erectile dysfunction: Bluish tinge
    Nitroglycerin for high blood pressure: Halos outlining objects
  • Antiseizure or psychotropic drugs: Complex, detailed hallucinations of people, animals, objects, and even whole scenarios
  • Antibiotics (cephalosporins and sulfa drugs): Disturbing, nightmarish hallucinations
  • Dopamine agonists for movement disorders like Parkinson’s (levodopa):16 From simple momentary hallucinations to complex, frightening ones

In some cases, dementia too can play a role in causing hallucinations that is in conjunction with medications.17 For instance, those with Parkinson’s disease may hallucinate because of medication as well as dementia.

6. Delirium

Delirium refers to a restless, excited, confused, and disturbed state of mind. In elderly individuals, it is commonly caused by prescription drugs (up to 40% cases), infections, stimulant intoxication and withdrawal (alcohol and drugs), and other underlying medical conditions.18

Neurotransmitter imbalances, inflammatory nerve damage, and insufficient blood flow to the brain are suspected to be involved.19

  • Urinary Tract Infections (UTIs):

UTIs comprise 25% of infections in the elderly, particularly women and residents of long-term care facilities.

Though there is some evidence suggesting an association between delirium and UTIs, possibly through UTI-induced behavioral changes, they are not conclusive.20 21 However, we know that infections can cause delirium and UTIs are nothing but bacterial infections. Individuals with UTIs may hallucinate, a symptom of delirium.

  • Surgery:

Anesthesia, other medications, and the buildup of inflammatory proteins during surgery can cause post-operative delirium. On the first two days following a major surgery, elderly individuals are likely to be delirious and hallucinate.22 Hallucinations tend to worsen at night.

Post-operative delirium is common in the elderly but often goes underdiagnosed. Timely diagnosis can prevent long-term complications like psychosis.

Hallucinations At Night

If you or a loved one is seeing figures or shadows or hearing sounds at night, the following reasons may have something to do with it.

  • Sleep-wake transitions: A common cause of hallucinations across all ages, sleep-wake transitions can trigger hallucinations. Hypnagogic hallucinations are experienced while falling asleep, while hypnopompic hallucinations are experienced while waking up. Sleep-related hallucinations often accompany sleep paralysis.
  • Sundowning: Sundowning is a confused, agitated, anxious, and aggressive state of mind that some people with dementia experience in the late afternoon, evening, or night (that is, as the sun goes down).23 Visual and auditory hallucinations are predominant.

Hallucinations Before Death

Hallucinations Before Death_Causes Of Hallucinations In The Elderly

Often people see deceased loved ones, the stairway to heaven, the light at the end of the tunnel, paradise-like scenes, or even unfamiliar figures and faces before they die. They may also hear God or angels talking to them. While spiritual and religious teachings offer easy-to-accept, inherited explanations for these occurrences, science too offers a rather tantalizing theory – hallucinations. Reduced blood flow to the retina, continual nervous excitement, and nightmare-like sleep states can trigger hallucinations before death.

A host of factors generally associated with old age and ill health can conjunctively cause hallucinations. These include:

  • Delirium due to high fever or an infection
  • Loss of vision or hearing
  • Dementia
  • Several medications

What a person sees or hears is largely dependent on their upbringing, culture, interests, and spiritual beliefs. For instance, a god-fearing person may see their god, while an atheist may see their younger self.

Advice For Caregivers24

  • Be indulgent: It is easy to get annoyed or angry with someone “unreasonably” reacting to unreal sights, sounds, smells, tastes, and feelings. Instead of arguing with them, realize that these sensations are very real to them. Show empathy and enquire whether the hallucinations are distressing and try to find a solution.
  • Create distractions: A good way to ease a person’s troubled mind is by shifting their focus. Ask them to do things they enjoy like listening to music, playing an instrument or game, or looking at old photo albums.
  • Maintain consistency: A person having hallucinations does well with a fixed routine in an unchanging surrounding.
  • Ensure a comfortable environment: Try and make the person as comfortable as possible in terms of where they live and the people they are surrounded by. Discomfort and awkwardness can aggravate their hallucinations. Arrange for proper lighting in the room to avoid misinterpretation of shadows. Covering mirrors may also help.
  • Investigate for underlying causes: Quickly scan the person’s body to identify wounds or bruises. Old people are prone to falling and may start hallucinating as a result of it. It also makes sense to assume they their hallucinations are real and look for the root cause. Weakened senses or decreased cognition may result in delusions, misinterpretations of real sensations that we may misidentify as hallucinations. Similarly, illusions may be misidentified as visual hallucinations and tinnitus as auditory hallucinations.

The first step toward dealing with hallucinations is by not demonizing them. While they can be pleasant and comforting, more often than not, they are tormenting and frightening. The best way forward is to be open about confessing our hallucinations to others while also being empathetic toward those experiencing them.