Unique to Older Adults

This section provides information to help older adults and their caregivers consider their disease or condition in conjunction with other health issues.

As older adults live longer, they may have more than one chronic disease.  Or, they may have a health problem that can lead to another condition or injury if not properly managed.   The older adult may also experience healthcare in various settings, such as the hospital, assisted living facility or at home. These situations can affect the health and function of the older adult and therefore require careful management to ensure proper care and improve or maintain quality of life.

Read on to learn more about the differences between delirium and dementia, other neurological disorders, and some important causes of delirium in older adults. 

Delirium is a common occurrence that can affect the health and quality of life for older persons. Delirium can be described as an acute change in mental status, usually occurring during a significant illness or stressful time. While delirium often occurs in people who have an underlying dementia, there are some important distinctions between the two.

Differences Between Delirium and Dementia

Any sudden change in behavior or mental functioning may be delirium.  Although it is difficult to tell the difference between delirium and dementia, it is important for your healthcare provider to do so because delirium can be reversible or treated right away.  Three of the key signs that a person is delirious are:

  • They have difficulty concentrating
  • There are changes in behavior, personality, or temperament
  • They have a change in level of consciousness (for example, being either super alert or drowsy)

If you suspect that someone in your care with a memory problem has become delirious, you must alert a healthcare professional. Delirium is considered a medical emergency.  One of the most common causes of delirium is medications, especially a reaction to a new medication.  Among the most common medications that cause delirium are narcotics, benzodiazepines, anti-cholinergic medications, anti-Parkinsonian drugs, and some anti-epileptic medications. Acute infection, surgery, or a new illness are other common causes.

Other Neurologic Disorders

Sometimes people who suffer strokes develop delirium.  This can occur without any other medical complications and regardless of whether the stroke was caused by a blood clot or a hemorrhage.  In addition, people with Parkinson’s disease are at a high risk for developing delirium. Depression may coexist with delirium or be mistaken for it. Always remember that depression and dementia come on slowly whereas delirium comes on quickly.

Some Important Causes of Delirium in Older Adults

Click the sections below to learn more about important causes of delirium in older adults. 

Urinary Retention or Fecal Impaction

Among the many reversible causes of delirium, urinary retention (not being able to empty the bladder) and fecal impaction are much more common in older people. Both of these conditions cause discomfort, but a delirious person may not be able to explain how they are feeling.

If you are caring for an older person, make sure to monitor the frequency of urination and bowel movements. Usually, urinary retention can be treated with repeated bladder catheterization or temporary insertion of a urinary catheter (not recommended for longer than 48 hours).  Fecal impaction can be helped by enemas, laxatives, and subsequent stool softeners. Careful attention to diet and exercise afterward will help to prevent an impaction from recurring.  

History of Alcohol or Substance Abuse

Delirium may be a symptom of alcohol or medication withdrawal if someone who is dependent on it stops consuming it suddenly (for example, benzodiazepines or opioids for sleep or pain).  Delirium may also occur when taking illegal drugs like cocaine, LSD, PCP, or amphetamines, or as an adverse effect of particular medications. The healthcare professional treating the older adult must be told exactly which drugs the person with delirium has taken to make sure that treatment is appropriate.

Some of the symptoms of delirium that are possible during severe alcohol withdrawal or substance abuse include:

  • Shaking and trembling (tremors)
  • Changed mental functions like agitation, excitement, irritability, confusion, restlessness
  • Shorter attention span
  • Deep sleep lasting a full day or longer, general sleepiness, or fatigue
  • Insomnia
  • Hallucinations
  • Sudden mood changes, including anxiety, depression, nervousness
  • Extra sensitivity to light, sound, or touch
  • Seizures
  • Headaches
  • Loss of appetite or nausea and vomiting
  • Heavy sweating
  • Heart palpitations (fast, sometimes uneven heartbeat) 

Infections or Sepsis: Respiratory, Urinary, Skin

Sometimes, a bacterial infection can cause delirium. The infections that are most often linked to delirium include urinary tract infections (in bladder or kidneys), lung infections (pneumonia) or skin infections (from skin ulcers or drug-resistant bacteria). Sepsis is when microorganisms invade the bloodstream and lead to the malfunction of various organs, including the brain, causing delirium. Sepsis may sometimes occur after an operation, or it may develop from an infection in another part of the body.

Delirium may also result from a fever caused by a viral infection such as influenza. Delirium is a strong indicator that a person is seriously ill, and symptoms may be present even before the infection has been discovered.


Some medicines commonly used in older adults can cause delirium in susceptible people. You must be particularly careful in the case of recently-started drugs taken to control depression, anxiety, or other mood or mental disorders. Even over-the-counter drugs that you can buy without a prescription (such as antihistamines, sleep medicines, and anti-ulcer medications) can lead to delirium.  

Medications that are known to cause delirium in some people include:

  • anticholinergics (available in many over-the-counter allergy and cold remedies, and sleeping medications)
  • some antidepressants (such as tricyclic antidepressants)
  • anti-epileptic medicines and barbiturates
  • sedatives and hypnotics like benzodiazepines (such as Valium)
  • sleep medications
  • pain relievers containing narcotic drugs
  • lithium
  • some allergy medicines, such as Benadryl
  • some anti-Parkinsonian medicines
  • digestive remedies such as H2 receptor blockers, anti-spasmodics, and anti-nausea drugs
  • antibiotics in the fluoroquinolone class (such as Cipro or Levaquin)
  • heart medicines such as digitalis

While these medicines may be prescribed by your healthcare provider, you should discuss any concerns you may have.  When prescribed, you should take the lowest effective doses available. Do not take over-the-counter medicines without talking to your healthcare provider.

Hospitalization or Environmental Change

Delirium is extremely common in older adults who have become hospitalized. Delirium is a well-known adverse effect of surgery, and is often evident in patients in the intensive care unit or in long-term care institutions. As a person’s cognitive awareness begins to decline they may be prone to experiencing delirium if hospitalized.  The absence of a familiar environment or recognizable family members, or even the frequent room changes that often occur in hospitals, all increase the disorientation that may lead to an episode of delirium.

To decrease the risk and chances of delirium, try to make sure the older adult has:

  • eyeglasses and hearing aids if these are normally used
  • a clock or watch in easy view
  • the name of the healthcare providers written clearly in sight
  • plenty of light during the day (preferably a window with natural light)
  • quiet and subdued light or darkness at night
  • a family member or friend present whenever possible. 


Delirium occurs most often in hospital post-anesthesia recovery units where patients are placed after general surgery. Pain management is of particular concern in these situations and it is important that the older adult communicates with their healthcare providers if they experience pain. Unrelieved pain itself may bring on delirium. If the older person has difficulty hearing, this may make it harder to inform caregivers of the severity and degree of pain they are in. If possible, hearing aids should always be worn to establish clear communication while in the hospital.

Falls and Fractures

Delirium itself may cause a fall. This is due to the confusion, excitability, inattention, and misunderstanding of environmental cues that occur when a person experiences delirium.  The risk of a falling increases with age. There are many reasons for the increased risk—including balance problems, weak muscles, lack of exercise, general frailty, sudden low blood pressure, malnutrition, and weak, thinning bones (osteoporosis). A fall can be injurious and result in a fracture, particularly if osteoporosis is also present. Common fractures after a fall are those of the hip, wrist, or a bone in the back (vertebra).  

Hearing and Vision Deficits

Poor hearing increases the risk for delirium. Not being able to communicate or understand verbal interactions places an older person in a frustrated and isolated state. This can have a detrimental effect on mental functions. If you or someone you are caring for is hard of hearing, make sure to use hearing aids and let healthcare professionals know that you have hearing loss.

Similarly, older people who need eyeglasses or who have impaired vision must make sure that their healthcare providers are aware of the difficulty seeing. If you are going to stay in the hospital, take your glasses with you and use them so that you are able to see your environment, the clock, and the individuals caring for you. To avoid episodes of delirium, it is important to be as aware and as comfortable as possible in the stressful environment of the hospital.


Dehydration is a harmful lack of water in your body. As you age, you may be less aware that you are dehydrated. This is because older people tend not to feel thirsty as readily as they did when they were younger, even though older people tend to have less fluid in their bodies.

A leading cause of dehydration among older adults is taking water pills (diuretics) for high blood pressure or heart failure. These pills cause frequent urination. Drinking coffee, tea, or alcohol also causes water to be lost from your body, since these beverages encourage urination. Fever, hyperventilation, or diabetes are also capable of causing water loss, as are problems in the digestive tract. Unfortunately, dehydration often goes unrecognized in frail older people.

Being dehydrated increases the risk of becoming delirious. To stay hydrated, drink plenty of fluids. Be particularly careful if you are taking water pills.

Electrolyte Abnormalities: Hyponatremia, Hypernatremia

With age, the body loses its ability to keep the amount of water in the body steady (water homeostasis). Specifically, the hormones that keep the sodium (salt) and water balance healthy may no longer work well. Hyponatremia (low sodium level in your blood) or hypernatremia (high sodium level) can result. These two conditions are especially common in nursing homes or hospitals when patients are unable to access water themselves.  

  • Hyponatremia. This may result from excessive fluids given through an IV or may be due to water pills. Also, kidneys are less efficient the older a person gets, and therefore, sodium balance is easier to upset in an older person. Also, some drugs are linked to hyponatremia (hydrochorothiazide or furosemide). Hyponatremia can cause, confusion and delirium. However, hyponatremia is usually a mild condition, and can be controlled by restricting fluids and stopping any medicines that may be making the condition worse. Then the underlying cause – be it kidney disease, heart failure, cirrhosis, or some other illness – must be treated promptly.
  • Hypernatremia.  This condition is usually caused by lack of adequate water intake.  Hypernatremia can affect the central nervous system and cause symptoms such as restlessness and irritability, fatigue and lethargy, muscular twitching, increased reflexes, or delirium.

Hypercalcemic Disorders

Older people can develop hyperparathyroidism, which is an overactive parathyroid gland (a gland in your neck). Hyperparathyroidism is more common in women, especially those over the age of 65 years.

When this happens, there are usually higher than normal levels of calcium in the blood—a condition known as hypercalcemia.

There are usually no symptoms if the calcium levels are only slightly higher than normal. However, if the calcium rises to higher levels, delirium may occur, along with nausea, vomiting, fatigue, or confusion.

Hypercalcemia may also be caused by a cancerous tumor. Therefore, if you or someone you are caring for exhibits the type of symptoms listed, you must call a healthcare provider promptly.

Last Updated July 2020