Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Insomnia


Related Terms

  • Disorder of Initiating and Maintaining Sleep (DIMS)
  • Dyssomnia
  • Mixed Sleep Apnea
  • Obstructive Sleep Apnea Syndrome
  • Sleep Disorder

Differential Diagnosis

Specialists

  • Cardiovascular Internist
  • Internal Medicine Physician
  • Neurologist
  • Otolaryngologist
  • Psychiatrist
  • Pulmonologist

Factors Influencing Duration

The cause of the insomnia, its persistence and severity, type of treatment, response to treatment, type of work performed, and presence of complications may influence disability.

Medical Codes

ICD-9-CM:
307.41 - Special Symptoms or Syndromes, Not Elsewhere Classified; Transient Disorder of Initiating or Maintaining Sleep; Hyposomnia Associated with Acute or Intermittent Emotional Reactions or Conflicts; Insomnia Associated with Acute or Intermittent Emotional Reactions or Conflicts
307.42 - Special Symptoms or Syndromes, Not Elsewhere Classified; Persistent Disorder of Initiating or Maintaining Sleep; Anxiety; Conditioned Arousal; Depression (Major) (Minor); Psychosis
327.02 - Organic Sleep Disorders; Insomnia Due to Mental Disorder
327.41 - Organic Parasomnia; Confusional Arousals
327.42 - Organic Parasomnia; REM Sleep Behavior Disorder
780.51 - Insomnia with Sleep Apnea, Unspecified
780.52 - Insomnia, Unspecified

Overview

Insomnia describes sleep disturbances that cause difficulty falling asleep, staying asleep, and returning to sleep after unplanned waking. Individuals with insomnia complain that the sleep they get is inadequate and does not leave them feeling refreshed or rested. As a result, individuals with insomnia feel that their daytime functioning is impaired by symptoms such as difficulty concentrating, mental sluggishness, irritability, decreased work performance, and daytime sleepiness.

Insomnia is a symptom, not a diagnosis or disorder. It has medical, psychological, behavioral, pharmaceutical, and environmental causes. Often several of these causes are present in a single individual. Insomnia can be transient, short-term, or chronic. Transient insomnia is familiar to almost everyone. It causes sleep difficulties lasting up to 1 week and is usually brought on by a change in schedule (e.g., jet lag) or a single stressful event, such as a job interview or work deadline. Transient insomnia normally disappears without treatment once the source of stress is removed or the individual has adjusted to the new schedule.

Short-term insomnia lasts up to six months. It is often connected to an on-going stressful situation such as a divorce, death of a loved one, or care of a seriously ill family member. It can also be caused by living in a situation where environmental factors make sleep difficult, such as living in an apartment above a noisy bar.

Chronic insomnia lasts for more than six months. It can be associated with a medical condition, a psychological disorder, certain medications, hormonal changes, and lifestyle situations such as shift work or frequent travel. Transient or short-term insomnia can develop into chronic insomnia as the individual becomes conditioned to poor sleep habits.

Common medical conditions that cause insomnia are those associated with chronic pain such as cancer, arthritis, nighttime cluster headaches, gastroesophageal reflux disease (GERD), and fibroneuralgia. Neurological disorders such as Parkinson's disease, restless leg syndrome (RLS) and periodic limb movement disorder (PLMD), which cause restlessness and uncontrolled movement during sleep, often cause chronic insomnia.

Medical conditions that decrease the level of oxygen in the blood can cause nighttime waking and insomnia. One common disorder of this type is sleep apnea. Individuals with sleep apnea stop breathing (apnea) for short intervals during sleep. True apnea occurs for 10 seconds or more, at least 5 times each hour. During the periods of apnea, the oxygen level in the blood drops causing the individual to wake suddenly and gasp for breath. Other medical conditions that cause insomnia due to a decrease in circulating oxygen include severe hypertension, congestive heart failure, and chronic obstructive pulmonary disease (COPD).

Hormonal changes may also cause insomnia. Hyperthyroidism, a disorder that increases basic metabolism, can cause insomnia. Pregnant women and those near menopause (perimenopausal) seem to have more difficulty with insomnia, as do older individuals of both sexes who are thought to produce less melatonin, a hormone associated with the regulation of sleep-wake cycles.

Insomnia is associated with certain psychological disorders, the most common of which is depression. Depression is believed to alter rapid eye movement sleep (REM), a necessary component for satisfactory sleep. Individuals with depression may experience early morning waking and difficulty returning to sleep. There appears to be a complex reinforcing relationship between insomnia and depression. Depression causes insomnia, but prolonged insomnia can cause depression (Rowley 2698). Individuals with schizophrenia or who are in the manic phase of bipolar disorder often have difficulty falling asleep (sleep-onset insomnia), and those with anxiety disorders, such as panic disorder or post-traumatic stress disorder may have difficulty either falling asleep or staying asleep (sleep-maintenance insomnia). Some individuals with thought disorders also misperceive their sleep state, reporting severe insomnia, when, in fact, their sleep is normal.

Certain drugs are a known cause of insomnia. Among the most common medications associated with this symptom are certain antidepressants (fluoxetine, bupropion, protriptyline) that may interfere with REM sleep. Other common medications that interfere with sleep include bronchodilator (often found in asthma medications), antihypertensives, corticosteroids, and decongestants. Caffeine is a stimulant found in some medications as well as coffee, tea, and cola. Sometimes individuals who are prescribed medications to help them sleep experience insomnia when they discontinue those medications (rebound insomnia).

Lifestyle factors also affect the ability to get adequate sleep. In addition to caffeine, nicotine and alcohol use can interfere with sleep cycles, as can virtually all street drugs. Heavy meals and spicy food shortly before bed can cause heartburn pain and GERD. Irregular sleep schedules and a noisy or uncomfortable sleep environment can also contribute to insomnia. Stress is also a major contributor to insomnia. Often several of these factors-medical, psychological, and environmental-combine to cause insomnia.

Incidence and Prevalence: Insomnia is common. About 20 to 40% of Americans report difficulty sleeping at some time during each year, and about 17% report that they consider their sleep difficulties serious (Bonds). In a 1991 study about one-third of Americans reported having trouble sleeping during the preceding year, with 10% saying their insomnia was severe; a World Health Organization study of 15 sites reported that about 27% of individuals reported problems with sleep (Rowley).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Older individuals are more likely to experience insomnia than younger individuals and women are more likely to report having insomnia than men (Rowley). Individuals who do shift work, especially those whose shifts change frequently, are at very high-risk of developing insomnia, as are individuals such as flight attendants, who travel frequently. In addition, individuals with the medical, psychological, and lifestyle conditions mentioned above are more likely to experience insomnia.

Source: Medical Disability Advisor



Diagnosis

History: A complete history is used to help determine the cause of insomnia. A sleep history is important in determining the individual's sleep environment, schedule, and sleep habits (collectively called sleep hygiene) and in diagnosing the cause of the insomnia. The timing of the insomnia (difficulty falling asleep, frequent waking, or early waking) is an important clue to the cause. A history of daytime symptoms is also taken.

A medical and psychiatric history helps the physician determine possible physical and psychological roots of insomnia, as well as determining if insomnia is being caused by medication. A social history helps to pinpoint any causes of stress or use of insomnia-inducing substances such as caffeine, alcohol, or street drugs.

Physical exam: A physical exam of individuals with sleep apnea may reveal that the back of the mouth and throat (oropharynx) are narrowed by excessive soft tissue folds, large tonsils or adenoids, and a prominent tongue. There may be evidence of a nasal obstruction or poor nasal airflow. The individual may have a short, thick neck (bull neck). Obesity is evident in many individuals with sleep apnea.

If the physician finds indications of a neurological disease such as RLS, the individual is referred to a neurologist for a more extensive physical exam. The physical exam for other causes of insomnia is often less revealing than the patient history.

Tests: Before testing, individuals are usually asked to keep a sleep log for 2 to 4 weeks recording the amount, timing, and quality of their sleep. This may help identify the cause of the insomnia and eliminate the need for more extensive sleep testing.

When sleep apnea is suspected, a test that monitors brain activity, eye movement, heart rate, and other body functions during sleep (polysomnography) can help confirm the diagnosis and determine the severity and frequency of episodes of low blood oxygen levels. The Multiple Sleep Latency Test (MSLT) detects how fast the individual falls asleep. Other tests may be needed such as monitoring the heart's electrical activity (electrocardiogram, or ECG), measuring blood oxygen levels (via oximetry or arterial blood gas), and measuring respiratory effort and airflow (pulmonary function tests). Specific tests are done appropriated to the suspected medical cause of insomnia.

Source: Medical Disability Advisor



Treatment

Since insomnia is a symptom, treatment depends on the cause of disturbed sleep. When insomnia is caused by stress or environmental factors, behavioral and lifestyle changes are often adequate treatment. Individuals are counseled to avoid stimulants throughout the day, get regular exercise, develop a regular bedtime schedule and routine, avoid heavy meals during the hours before bed, eliminate noise and light distractions, and initiate other changes in sleep hygiene. Sometimes individuals benefit from sleeping in places other than their bed or in reserving the bed for sleep only, instead of reading or watching television in bed. Relaxation therapy, such as progressive relaxation of muscles, guided imagery, or relaxation biofeedback may be helpful.

Short-term (2 to 3 week) courses of hypnotic medication may prove useful in treating some types of insomnia. Hypnotics with a rapid onset are used to treat difficulties falling asleep, while drugs that remain effective for longer periods are used to treat difficulties staying asleep.

When insomnia is caused by a medical or psychiatric condition, the condition is treated. Medications that cause insomnia may be changed or eliminated. If the individual wakes frequently because of low blood levels of oxygen (sleep apnea, COPD), supplemental oxygen may help raise blood oxygen levels. Pressure applied through the nasal passages during inhalation (nasal continuous positive airway pressure or NCPAP; bi-level positive airway pressure or BiPAP) may be used. In severe cases of obstructive sleep apnea, an operation on the uvula may be necessary.

Source: Medical Disability Advisor



Prognosis

Successful treatment of insomnia depends on treating the causes of sleep disturbance. Transient insomnia usually resolves with minor behavioral and environmental changes. Successful treatment for more persistent types of insomnia usually depends on successful treatment of the conditions causing the symptom.

Source: Medical Disability Advisor



Complications

Most complications result from the underlying cause of insomnia. However, insomnia can put individuals at higher risk for vehicular and workplace accidents. It can also cause irritability that interferes with professional and personal relationships.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Daytime sleepiness and poor concentration may interfere with job performance and the safe operation of vehicles and machinery. Job reassignment may be necessary on a case-by-case basis. Particular attention should be given to those whose jobs require prolonged period of alertness, such as pilots, professional drivers, and surgeons.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • How long has insomnia persisted?
  • Have complete sleep, medical, psychiatric, and social histories been done?
  • Has individual kept a sleep log for 2-4 weeks?
  • Has individual had a sleep study done?
  • Have medical and psychiatric causes of insomnia been investigated?

Regarding treatment:

  • Have medical and psychiatric conditions been treated appropriately?
  • Has individual been compliant in eliminating potential causes of insomnia such as caffeine, street drugs, and alcohol?
  • Has individual received sleep hygiene education?
  • Has individual eliminated or reduced potential environmental causes for insomnia?
  • Does individual need supplemental oxygen at night?

Regarding prognosis:

  • Is individual's employer able to accommodate any necessary restrictions?
  • Does individual have any conditions that may affect his or her ability to recover?
  • Is individual required to have extraordinary mental alertness for work tasks?
  • Would individual benefit from additional psychological counseling or sleep hygiene education?

Source: Medical Disability Advisor



References

Cited

Bonds, Curley L. "Sleeping Disorders." eMedicine. Eds. Denis F. Darko, et al. 16 Nov. 2004. Medscape. 10 Dec. 2004 <http://emedicine.com/med/topic609.htm>.

Rowley, James. "Insomnia." eMedicine. Eds. Gregory Tino, et al. 16 Nov. 2004. Medscape. 10 Dec. 2004 <http://emedicine.com/med/topic2698.htm>.

Source: Medical Disability Advisor






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