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Can a coma last for years?

A coma is a prolonged state of unconsciousness. It is one of the most unsettling and emotionally painful conditions that family members can face. The question of whether a coma can last for years is a common concern for families with loved ones in this state. The uncertainty of the situation and not knowing when or if their loved one will wake up takes a tremendous toll.

In this article, we will provide a thorough overview of comas, examining how long they can potentially last as well as other critical factors. We will review the different types and causes of coma. Additionally, we will discuss the day-to-day care required for coma patients and what families can expect during this challenging time.

What is a Coma?

A coma is defined as a state of prolonged unconsciousness lasting more than 6 hours in which a person cannot be awakened and fails to respond normally to pain, light, or sound. It is a result of injury or illness that affects the brain’s function. Even though a coma patient is unconscious and unresponsive, the brain remains active as it works to heal itself.

Comas are categorised by their depth:

Shallow Coma

In a shallow coma, also called a medically induced coma, the patient can show subtle responses, such as moving fingers or eyelids when stimulated. Doctors may intentionally put a patient into a shallow coma by administering medication to allow the brain time to heal. These comas typically do not last longer than 2 to 3 weeks.

Deep Coma

A deep coma is characterized by no eye opening, movement or response to stimuli. Patients in this state have lost their brainstem reflexes and show no signs of awareness. Deep comas have a poorer prognosis compared to shallow comas in terms of regaining consciousness.

What Causes Comas?

There are several potential causes of coma including:

  • Traumatic brain injury from events like automobile accidents, falls or physical abuse
  • Lack of oxygen to the brain which can occur during cardiac arrest, respiratory failure, carbon monoxide poisoning or drowning
  • Stroke which deprives blood and oxygen to parts of the brain
  • Infections such as encephalitis and meningitis
  • Severe metabolic disturbances like kidney or liver failure
  • Brain tumors or aneurysms which create pressure and damage
  • Toxicity from substances like illegal drugs, sedatives, and alcohol

In some cases, doctors are unable to determine an exact cause which is called a cryptogenic coma. Patients who remain in coma with an unknown origin generally have a poorer outlook.

How Long Can a Coma Last?

There is no definite time limit for how long a coma can last. Each patient’s situation is different based on what caused the coma and the severity of the damage. Comas can persist for days, weeks, months and sometimes even years. Here is an overview of general time frames:

Short-Term Coma

A short-term coma usually lasts several days to 2 weeks. Causes include drug toxicity, seizures or minor trauma. The majority of patients who recover consciousness do so within this window.

Prolonged Coma

A prolonged coma lasts between 2 and 4 weeks. More severe brain injuries or lack of oxygen can result in a coma of this duration. The longer a patient remains unconscious, the less likely their prognosis becomes. After 4 weeks, the chance of recovery declines rapidly.

Persistent Coma

A persistent coma is characterized by a lack of awareness lasting longer than 4 weeks. Though uncommon, some patients remain in this state for months or years. The longest reported coma lasted 37 years. Patients who emerge from a persistent coma often have major disabilities. However, recovery has been seen even after many years unconscious.

Coma Patient Care

Caring for a coma patient is an intensive, full-time job requiring extensive medical supervision, usually in an intensive care unit. Because the patient cannot move, speak or eat, caregivers must tend to all their needs. This includes:

  • Monitoring vital signs like heart rate, blood pressure and breathing
  • Turning the body every 2-3 hours to prevent bedsores
  • Feeding and hydrating through feeding tubes and IV fluids
  • Clearing the airways with suctioning
  • Physical therapy to maintain joint mobility
  • Medications to stabilize medical issues

Doctors also look for signs of neurological recovery like eye opening and sleep cycles. Families keep a constant bedside vigil talking to and stimulating their loved one in hopes of a response. The extensive care required makes prolonged comas financially and emotionally draining. Families bear a tremendous burden but do all they can clinging to hope.

Coma Emergence

Emerging from a coma is a gradual process marked by a return of sleep/wake cycles and certain reflexes. Eventually the patient can open their eyes, communicate and follow commands. The speed of recovery varies by how long the coma lasted.

Coming out of a short-term coma typically occurs faster, within days or weeks after injury. Patients recover more cognitive and physical abilities the shorter the length of unconsciousness.

For longer comas, emerging can take months or years as the brain rewires itself. These patients often awaken confused, agitated and disoriented. They require extensive rehabilitative therapy to relearn how to walk, eat and take care of themselves.

Coma Outcomes

The ultimate outcome for a coma patient depends on the severity of injury and how quickly consciousness returns. While emerging from a coma is a major step, the survivor is often left with significant impairments.

Possible disabilities include:

  • Memory loss
  • Difficulty thinking and communicating
  • Paralysis or loss of movement
  • Trouble swallowing and eating
  • Loss of bowel and bladder control
  • Seizures
  • Chronic pain or fatigue

Even after awakening, the person may fall back into periods of unresponsiveness. The longer the coma duration, the higher the likelihood of permanent deficits. Patients who have been in a coma for many months or years often remain severely disabled.

Some patients never emerge from the coma state due to the extent of neurologic damage. The brain stem, which controls breathing and circulation, may be irreparably injured leading to death. If the coma continues with no signs of improvement, families may eventually need to consider withdrawing life support.

Coma Recovery Examples

Though each case is unique, real world examples help illustrate what’s possible after prolonged unconsciousness:

Recovery After 19 Years in a Coma

In 1991, Munira Abdulla suffered a severe brain injury in a car accident. She stayed in a coma for nearly two decades before suddenly speaking one day in a care home. Though she remained in a wheelchair, her son said she could now communicate and recognize family members.

Emergence After 6 years Unconscious

Terry Wallis was left in a coma after a car wreck in 1984. In 2003, he unexpectedly regained speech and awareness. He slowly recovered ability to eat, walk and care for himself though he remains disabled. MRI scans show his brain formed new neural pathways during the coma.

Consciousness After 27 Years Unresponsive

In 1991, Jan Grzebski woke up after being in a coma from a train accident for over a quarter century. During that time, the world changed dramatically with collapse of the Soviet Union and invention of the internet. Grzebski described feeling lost and confused trying to grasp how much time passed.


Comas represent one of the great medical mysteries. While typically lasting days to weeks, comas can persist for months, years or even decades in extreme cases. Only time will tell when or if a patient will emerge from prolonged unconsciousness. Though recovery is challenging, stories of remarkable awakenings offer hope.

With proper medical care, families can keep their loved one stable. But the extensive nursing and therapy required make extended comas an immense physical, emotional and financial burden. Families courageously coping with this ambiguity deserve tremendous support. Ultimately, the duration and outcome depends on the unique circumstances of the brain injury. While a coma lasting for years is highly uncommon, it remains a possibility.