brain, spinal cord, and nerve disorders
Stupor and Coma
Causes of Stupor and Coma
The various levels of impaired consciousness—lethargy, obtundation, stupor, and coma—have the same causes, of which there are many. Most commonly, the cause is A toxic substance, such as Carbon Monoxide Poisoning None A drug, such as Alcohol Use , an A metabolic abnormality, such a very low blood sugar level ( Hypoglycemia ) or very high blood sugar level ( A disorder that makes nerve cells in the brain malfunction and communicate less well, such as Liver Failure or A severe infection in or around the brain, such as Introduction to Meningitis or a A severe infection elsewhere in the body, such as Sepsis and Septic Shock (a bodywide infection) Severe or prolonged Seizure Disorders None Inadequate blood flow to the brain, as occurs when the heart stops ( Cardiac Arrest and CPR ) Overview of Head Injuries , such as Disorders that increase pressure within the skull (intracranial pressure), including certain Overview of Brain Tumors and Some disorders interfere with the delivery of needed substances to the brain or with the body’s ability to use them. Examples are A very low or very high blood sugar level (hypoglycemia or hyperglycemia) A very low level of oxygen in the blood, as occurs in Respiratory Failure or The sudden stopping of the heart’s pumping ( Cardiac Arrest and CPR ) or breathing (respiratory arrest) Blood delivers oxygen and essential nutrients (such as fats, sugars, minerals, and vitamins) to the body's tissues. Thus, when blood flow to the brain is decreased, the brain is deprived of oxygen and essential nutrients. The brain may also be deprived of oxygen when the lungs are not functioning normally, as occurs in respiratory failure. The brain can be deprived of nutrients when a disorder (such as hypoglycemia) causes levels of nutrients in the blood to be low. Having Diabetes Mellitus (DM) increases the risk of stupor or coma because diabetes can cause the blood sugar level to become too high or, when treatment is too aggressive, too low. When blood sugar levels are very high, people become Other disorders can cause cells throughout the body to malfunction. Often, brain cells are affected the most. These disorders include Liver Failure None Overview of Kidney Failure None An underactive thyroid gland ( Hypothyroidism ) A very low or high body temperature ( Hypothermia or Very low or high levels of Overview of Calcium's Role in the Body or Thiamin Deficiency None Other common causes are disorders that affect the areas of the brain that control consciousness. These disorders include the following: Overview of Head Injuries None Complications of stroke None Any disorder that increases pressure within the skull (intracranial pressure) can impair consciousness. A mass in the brain, such as an accumulation of blood (hematoma), a tumor, or an abscess, can impair consciousness indirectly by putting pressure on the areas of the brain that control consciousness. A structural abnormality can block the flow of cerebrospinal fluid in the brain, increasing pressure within the skull. Cerebrospinal fluid is the fluid that flows through the tissues covering the brain and spinal cord and fills the spaces within the brain. Some structural abnormalities are present at birth. A large mass can push the brain against the relatively rigid structures inside the skull, damaging brain tissue. If the areas of the brain that control consciousness are affected, stupor or coma results. If the pressure is high enough, the brain may be forced through a small natural opening in the relatively rigid sheets of tissue that separate the brain into compartments. This life-threatening disorder is called Herniation: The Brain Under Pressure . Herniation can further damage brain tissue, making an already dire condition worse. Having had a stroke or having another disorder that affects brain function makes the brain more susceptible to other disorders that can impair consciousness. Commonly, consciousness is impaired by drinking too much Alcohol Use or taking too much of certain drugs, such as Taking several drugs (to treat several disorders) is also a common cause, partly because taking several drugs increases the risk of interactions between drugs. Marijuana , including medical marijuana, sometimes causes the brain to malfunction, resulting in impaired consciousness and sometimes seizures. Occasionally, taking certain Antipsychotic drugs results in an unresponsive state called Occasionally, people who have a psychiatric disorder or those who are psychologically stressed may appear unresponsive. For example, people who learn that they have cancer or that their spouse is going to leave them may collapse and not respond when they are spoken to or touched. Yet, such people may be aware of what is happening around them, and their brain may be functioning normally. Based on the results of the Diagnosis , doctors can usually determine how much a psychiatric disorder or psychologic distress contributes to what appears to be impaired consciousness and whether the person is pretending. Aging alone does not increase the risk of impaired consciousness. However, age-related changes make impaired consciousness in older people a particular concern (see Essentials for Older People: Coma and Stupor ). For example, some disorders that are more common among older people (such as high blood pressure or diabetes) can increase the risk of impaired consciousness if another problem develops. Common problems that can trigger impaired consciousness in older people include Reactions to drugs Dehydration None Infections Development of a new disorder (such as stroke or heart failure) or worsening of a disorder they already have 