Coma – Symptoms and Causes

ByJanis Updated

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A coma is a serious medical condition where someone loses consciousness for an extended period. This is not like sleep, the person cannot be awakened and shows no normal brain responses.

Several things can cause comas, including head injuries, strokes, brain tumors, and substance abuse. Medical conditions like diabetes or infections can also lead to a coma.

When someone falls into a coma, immediate medical attention is crucial.

Doctors typically perform blood tests and brain scans to find the cause and begin proper treatment quickly. This fast response helps protect the brain from further damage.

Most comas don’t last longer than a few weeks. If someone remains unconscious for a longer time, they might enter what doctors call a persistent vegetative state or experience brain death.

These conditions happen when the brain has suffered severe damage.

Signs of a Coma

A person in a coma typically shows several key signs. Their eyes remain closed. The pupils don’t react when exposed to light.

Their arms and legs don’t move on purpose, only making reflex movements. They don’t react to pain except with reflexes. Their breathing pattern may be uneven or irregular.

Medical Help Needed Right Away

A coma is always a serious emergency. If someone appears to be in a coma, call 911 or your local emergency number immediately.

Quick medical care is essential. Don’t wait to see if the person wakes up on their own.

Causes

A coma can result from several different medical conditions. Brain trauma from accidents or violence often leads to comas through direct damage to brain tissue.

When blood flow to the brain stops or slows during a stroke, brain cells can die, possibly causing a comatose state.

Brain tumors create pressure inside the skull, potentially triggering a coma. For people with diabetes, extremely high or low blood sugar levels can disrupt brain function and lead to unconsciousness.

Oxygen deprivation, which may occur during drowning or cardiac arrest, can cause lasting brain damage and coma. Serious infections like encephalitis and meningitis create inflammation in or around the brain, sometimes resulting in a coma.

Long-lasting seizures may exhaust the brain and lead to a comatose state. Exposure to harmful substances such as carbon monoxide or lead can damage brain cells and cause unconsciousness.

Common Coma Causes:

  • Brain injuries from accidents
  • Strokes (blocked or burst blood vessels)
  • Tumors pressing on brain tissue
  • Diabetic blood sugar emergencies
  • Lack of oxygen to the brain
  • Severe brain infections
  • Prolonged seizure activity
  • Toxic substance exposure
  • Drug or alcohol overdose

Risk Factors

Several health conditions can lead to a coma. Serious brain injuries from accidents are common causes. Strokes and bleeding in or around the brain can also result in coma. Brain tumors may cause pressure that affects consciousness.

People with diabetes face risks when their blood sugar becomes extremely high or low. Certain health issues like low thyroid function or decreased sodium levels in the blood can trigger a coma state.

Very low blood pressure from severe heart failure may reduce blood flow to the brain.

Epilepsy presents another risk, especially when seizures last longer than five minutes or occur back-to-back without recovery. Serious infections affecting the brain or bloodstream, including meningitis, encephalitis, and sepsis, can lead to coma.

Other risk factors include:

  • Near drowning (reduces oxygen to the brain)
  • Excessive alcohol consumption
  • Illegal drug use
  • Exposure to toxins like carbon monoxide or lead

Older adults face higher coma risks, particularly those with:

  • Existing brain diseases
  • Chronic conditions (diabetes, high blood pressure, kidney disease)
  • Multiple medications that might interact or lead to accidental overdose

Possible Complications

Recovery from a coma varies greatly among patients. Some people may gradually regain consciousness and function, while others face more serious outcomes. These outcomes can include:

  • Death
  • Entering a persistent vegetative state
  • Recovering with disabilities (ranging from minor to severe)

During the coma period, patients are at risk for several physical complications due to their immobility and unconscious state. Common problems include:

Physical Complications:

  • Bedsores (pressure ulcers)
  • Urinary tract infections
  • Blood clots in the legs (deep vein thrombosis)
  • Muscle wasting
  • Pneumonia

These complications can develop quickly and require careful monitoring by healthcare staff. Regular position changes, specialized mattresses, and preventative medications may help reduce these risks.

The longer a person remains in a coma, the greater the chance of developing complications. Family members should work closely with the medical team to understand treatment options and potential outcomes.

Health Writer

Janis's areas of expertise include nutrition, exercise, stress management, and mental health. She is passionate about educating and empowering people to take control of their health and make positive changes that can last a lifetime. Janis believes that small, sustainable changes are the key to long-term success, and she works with her clients to develop personalized plans that fit their individual needs and lifestyles.