What Is Decreased Consciousness?
The major characteristics of consciousness are alertness and
being oriented to place and time. Alertness means that you are able to respond
appropriately to the people and things around you. Being oriented to place and
time means that you know who you are, where you are, where you live, and what
time it is.
When consciousness is decreased, your ability to remain awake,
aware, and oriented is impaired. Impaired consciousness is a medical emergency.
Consciousness and the Brain
The brain is the main organ responsible for maintaining
consciousness. Your brain requires certain amounts of oxygen and glucose in
order to function properly.
Many substances you consume can affect your brain chemistry. These
substances can help to maintain or decrease consciousness. For example,
caffeine is a stimulant, which means that it raises your levels of brain
activity. Caffeine can be found in many foods you eat every day, such as
coffee, soda, and chocolate. On the other hand, painkillers and tranquilizers
make you drowsy. This side effect for these substances is a form of impaired
Diseases that damage your brain cells can also cause impaired
consciousness. A coma is the most severe level of consciousness impairment.
Symptoms of Decreased Consciousness
Symptoms that may be associated with decreased consciousness include:
- loss of bowel or bladder function
- poor balance
- difficulty walking
- irregular heart beat
- rapid pulse
- low blood pressure
- weakness in the face, arms, or legs
Types of Decreased Consciousness
Levels of impaired consciousness include confusion, disorientation,
delirium, lethargy, stupor, and coma.
Confusion is marked by the absence of clear thinking and may
result in poor decision-making.
Disorientation is the inability to understand how you relate to
people, places, objects, and time. The first stage of disorientation is when
you are disoriented with respect to time (years, months, days). This is
followed by disorientation with respect to place, which means you may not know
where you are.
Loss of short-term memory follows disorientation with respect to
place. The most extreme form of disorientation is when you lose the memory of
who you are.
If you are delirious, your thoughts are confused and illogical.
People who are delirious are often disoriented. Their emotional responses range
from fear to anger. People who are delirious are often highly agitated.
Lethargy is a state of decreased consciousness that resembles
drowsiness. If you are lethargic, you may not respond to stimulants like the
sound of an alarm clock or the presence of fire.
Stupor is a deeper level of impaired consciousness in which it is
very difficult for you to respond to any stimuli, except for pain.
Coma is the deepest level of impaired consciousness. If you are
in a coma, you can’t respond to any stimulus, not even pain.
Common Underlying Causes of Decreased Consciousness
Drugs, alcohol, substance abuse, certain medications, epilepsy,
low blood sugar, stroke, and lack of oxygen to the brain are common causes of decreased
Other underlying causes of decreased consciousness include:
- cerebral hemorrhage
- dementia (Alzheimer’s)
- head trauma
- heart disease
- heat stroke
- liver disease
- uremia (end stage kidney failure)
What to Expect When You See the Doctor
Diagnosis and treatment of decreased consciousness begins with a
complete medical history and physical examination, which includes a detailed
neurological evaluation. Your doctor will want to know about any medical
problems you have (such as diabetes, epilepsy, or depression), and any
medications you are taking (such as insulin or anticonvulsants). They will also
ask if you have a history of abusing illegal or prescription drugs or alcohol.
In addition to your complete history and physical, the doctor may
order the following tests:
- CBC (complete blood count): finds if you have a
low hemoglobin level, which indicates anemia. An elevated white blood cell
count indicates infections, such as meningitis or pneumonia.
- toxicology screen: detects the presence and
levels of medications, illegal drugs, and poisons in your system
- electrolyte panel: measures levels of sodium,
potassium, chloride, and bicarbonate
- liver function tests: measure the health of your
- electroencephalogram (EEG): uses scalp
electrodes to evaluate brain activity
- electrocardiogram (EKG): evaluates heart rate,
rhythm, and health
- chest X-ray: evaluates the heart and lungs
- CAT scan of the head: uses X-rays to make
high-resolution images of the brain that can help find any abnormalities
- MRI of the head: uses nuclear magnetic resonance
to make high-resolution images of the brain
Treating Decreased Consciousness
Treatment for decreased consciousness depends on what’s causing
it. You may need to change medications, begin new treatment, or simply treat
the symptoms to address the underlying cause. For example, you need emergency
medical treatment and possibly surgery to treat a cerebral hemorrhage. On the
other hand, there is no cure for Alzheimer’s, so your healthcare team will work
with you to come up with strategies to treat any symptoms and maintain quality
of life as long as possible.
Talk to your doctor as soon as you think you may be experiencing
decreased consciousness so they can start your treatment as soon as possible.
Outlook for Decreased Consciousness
Decreased consciousness can be a sign of a serious condition.
Getting prompt medical attention is important for your long-term outlook. Your
outlook can become worse the longer you spend in less than full consciousness.