A coma, sometimes also called persistent vegetative state, is a profound or deep state of unconsciousness lasting more than 6 hours. Persistent vegetative state is not brain-death. An individual in a state of coma is alive but unable to move or respond to his or her environment. A person in a coma cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions.

Coma may occur as a complication of an underlying illness, or as a result of injuries, such as head trauma. Conditions that may result in a coma include:

  • Intoxication – such as illicit drug abuse, overdose or misuse of over the counter medications, prescribed medication, or controlled substances
  • Metabolic abnormalities
  • Central nervous system diseases
  • Acute neurologic injuries such as strokes or herniations
  • Hypoxia
  • Hypothermia
  • Hypoglycemia
  • Traumatic injuries such as head trauma caused by falls or vehicle collisions

It may also be deliberately induced by pharmaceutical agents in order to preserve higher brain functions following a brain trauma, or to save the patient from extreme pain during healing of injuries or diseases.

Individuals in such a state have lost their thinking abilities and awareness of their surroundings, but retain non-cognitive function and normal sleep patterns. Even though those in a persistent vegetative state lose their higher brain functions, other key functions such as breathing and circulation remain relatively intact. Spontaneous movements may occur, and the eyes may open in response to external stimuli. Individuals may even occasionally grimace, cry, or laugh. Although individuals in a persistent vegetative state may appear somewhat normal, they do not speak and they are unable to respond to commands.

Once an individual is out of immediate danger, the medical care team focuses on preventing infections and maintaining a healthy physical state. This will often include preventing pneumonia and bedsores and providing balanced nutrition. Physical therapy may also be used to prevent contractures (permanent muscular contractions) and deformities of the bones, joints, and muscles that would limit recovery for those who emerge from coma.

The outcome for coma and persistent vegetative state depends on the cause, severity, and site of neurological damage. Individuals may emerge from coma with a combination of physical, intellectual, and psychological difficulties that need special attention. Recovery usually occurs gradually, with some acquiring more and more ability to respond. Some individuals never progress beyond very basic responses, but many recover full awareness.

Individuals recovering from coma require close medical supervision. A coma rarely lasts more than 2 to 4 weeks. Some patients may regain a degree of awareness after persistent vegetative state. Others may remain in that state for years or even decades. The most common cause of death for someone in a persistent vegetative state is infection, such as pneumonia.

Thyroid Disorders

Your thyroid gland is a small, butterfly-shaped gland located in your neck just below your Adam’s apple. The thyroid produces hormones that affect your body’s metabolism, which controls how your body uses and stores energy from the food you eat as well as how certain organs function.

When your thyroid is not functioning properly, it can affect:

  • Body weight
  • Energy level
  • Skin
  • Muscle strength
  • Memory
  • Heart rate
  • Cholesterol level

Thyroid problems are very common, especially among women, affecting about one in every eight North American women at some point during their life. However, thyroid problems often are misdiagnosed because their symptoms sometimes develop gradually and are confused with other medical problems.

The most common thyroid disorders occur either when your thyroid fails to produce enough hormones, a condition called hypothyroidism, or when your thyroid produces an excessive amount of hormones, causing hyperthyroidism. Most thyroid disorders can be diagnosed with a simple blood test, called a thyroid stimulating hormone (TSH) test.

Treatment typically involves surgery, medications and radioactive iodine.


Hyperthyroidism occurs when the thyroid produces excess thyroid hormone.

Hyperthyroidism is a common disorder affecting over two million North Americans, most of whom are women.

The most common cause of the condition is Graves’ disease, which accounts for 85 percent of cases. Hyperthyroidism also can result from nodular goiter, a condition in which an inflammation of the thyroid occurs due to viral infections or other causes, ingestion of excessive amounts of thyroid hormone, and ingestion of excessive iodine.

Initially, many patients do not experience any symptoms and therefore do not get diagnosed with hyperthyroidism until it is more advanced. In older people, some or all of the typical symptoms of hyperthyroidism may be absent, and the patient may just lose weight or become depressed.

Typical symptoms of the condition include:

  • Nervousness and irritability
  • Increased resting heart rate, which causes heart palpitations
  • Heat intolerance and increased sweating
  • Tremors
  • Weight loss with increase in appetite
  • Frequent bowel movements
  • Thyroid enlargement causing a lump in the neck
  • Pretibial myxdemia, which causes a thick redness on the front of legs and typically occurs with Graves’ disease
  • Thin, delicate skin and irregular fingernail and hair growth
  • Menstrual disturbance, such as decreased flow
  • Mental disturbances
  • Sleep disturbances, including insomnia
  • Changes in vision, eye irritation or exophthalmos, which is a protrusion of the eyes that typically occurs with Graves’ disease


Hypothyroidism occurs when the thyroid gland fails to produce enough thyroid hormone. Without enough thyroid hormone, the body becomes tired and run down. Every organ system slows, including the brain, which affects concentration; the gut, causing constipation; and metabolism — the rate at which the body burns energy — resulting in weight gain. Although there are many different causes of hypothyroidism, the resulting effect on the body is the same.

The most common cause of hypothyroidism is Hashimoto’s thyroiditis, a disease in which the body’s immune system attacks the thyroid gland. Failure of the pituitary gland to secrete a hormone to stimulate the thyroid gland, called secondary hypothyroidism, is a less common cause of hypothyroidism. Other causes include congenital defects, surgical removal of the thyroid gland, irradiation of the gland and inflammatory conditions.

The condition is more common in women and people over the age of 50. Other risk factors include thyroid surgery and exposure of the neck to X-ray or radiation treatments.

The symptoms of hypothyroidism depend on the amount of decrease in thyroid hormone and the duration of time in which the decrease has been present. Most patients experience mild symptoms, which are often confused with other problems. Symptoms may include:

  • Fatigue
  • Joint or muscle stiffness
  • Decreased hearing
  • Weight gain
  • Dry skin
  • Sensitivity to cold
  • Coarseness or loss of hair
  • Goiter, or an enlarged thyroid causing a lump in the neck
  • Constipation
  • Memory and mental impairment
  • Depression
  • Irritability
  • Irregular or heavy menstruation
  • Slowed heart rate
  • Decreased libido

With proper treatment, patients with hypothyroidism can regain full control of their lives and completely eliminate symptoms.