Coma: Facts, Causes, Symptoms & Treatments

Picture of Coma


What is Coma?

A coma is a prolonged state of unconsciousness. During a coma, a person is unresponsive to his or her environment. The person is alive and looks like he or she is sleeping. However, unlike in a deep sleep, the person cannot be awakened by any stimulation, including pain.

Facts on Coma

Here are some key points about coma. More detail and supporting information is in the main article.

  • Patients in a coma do not react to external stimuli
  • Comatose patients do not have sleep-wake cycles
  • Comas can arise for a number of reasons, including intoxication and nervous system disease
  • Depending on the cause, a vegetative state can occur rapidly or gradually
  • Sometimes a stroke can result in a coma
  • Coma patients do not show normal reflex responses
  • A number of tests will be carried out on the patient, often including a spinal tap and MRI scan
  • The Glasgow Coma Scale helps assess the severity of the coma
  • If there is brain swelling, surgery may be necessary to relieve pressure

Causes of Coma?

Comas can be caused by different things, including:

  • a severe injury to the head that hurts the brain
  • seizures
  • infections involving the brain
  • brain damage caused by a lack of oxygen for too long
  • an overdose (taking too much) of medicine or other drugs
  • a stroke
  • chemical imbalances (in the body from other illnesses)

When one of these things happens, it can mess up how the brain’s cells work. This can hurt the parts of the brain that make someone conscious, and if those parts stop working, the person will stay unconscious.

Symptoms of Coma

The signs and symptoms of a coma commonly include:

  • Closed eyes
  • Depressed brainstem reflexes, such as pupils not responding to light
  • No responses of limbs, except for reflex movements
  • No response to painful stimuli, except for reflex movements
  • Irregular breathing

Caring for and monitoring a person in a Coma

Doctors assess a person’s level of consciousness using a tool called the Glasgow Coma Scale. This level is monitored constantly for signs of improvement or deterioration. The Glasgow Coma Scale assesses three things:

  • eye opening – a score of one means no eye opening, and four means opens eyes spontaneously
  • verbal response to a command – a score of one means no response, and five means alert and talking
  • voluntary movements in response to a command – a score of one means no response, and six means obeys commands

Most people in a coma will have a total score of eight or less. A lower score means someone may have experienced more severe brain damage and could be less likely to recover.

In the short term, a person in a coma will normally be looked after in an intensive care unit (ICU). Treatment involves ensuring their condition is stable and their body functions, such as breathing and blood pressure, are supported while the underlying cause is treated.

In the longer term, healthcare staff will give supportive treatment on a hospital ward. This can involve providing nutrition, trying to prevent infections, moving the person regularly so they don’t develop bedsores, and gently exercising their joints to stop them becoming tight.

Treatment for Coma

At the outset of a coma, it is important to diagnose and treat the underlying cause. Depending on the severity of the coma, the patient may require life-saving resuscitative measures. Once medically stable, treatments can be used to correct the underlying problem that is causing the coma.

For patients in a prolonged coma, or persistent vegetative state, the focus is on preventing infections, providing nutrition, and maintaining the patient’s physical health. This includes proper nutrition and prevention of infections such as pneumonia (a common cause of death in those in a long-term coma) and bedsores. Sometimes, physical therapy is administered to prevent bone, joint, or muscle deformities.