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.

Hypothyroidism


Related Terms

  • Myxedema
  • Thyroid Insufficiency
  • Underactive Thyroid Gland

Differential Diagnosis

Specialists

  • Endocrinologist
  • Family Physician

Comorbid Conditions

  • Immune system disorders
  • Infection
  • Pre-existing heart condition

Factors Influencing Duration

Factors include the severity of symptoms, presence of complications, and the individual's response to treatment. Symptoms can recur as the underlying disease progresses.

Medical Codes

ICD-9-CM:
244.0 - Acquired Hypothyroidism; Postsurgical Hypothyroidism
244.1 - Acquired Hypothyroidism; Other Postablative Hypothyroidism; Hypothyroidism following Therapy, Such as Irradiation
244.2 - Acquired Hypothyroidism; Iodine Hypothyroidism; Hypothyroidism Resulting from Administration or Ingestion of Iodide
244.3 - Acquired Hypothyroidism; Other Iatrogenic Hypothyroidism; Hypothyroidism Resulting from: P-aminosalicylic Acid [PAS], Phenylbutazone, Resorcinol, Iatrogenic Hypothyroidism NOS
244.8 - Acquired Hypothyroidism; Other Specified Acquired Hypothyroidism; Secondary Hypothyroidism NEC
244.9 - Acquired Hypothyroidism; Unspecified Hypothyroidism; Hypothyroidism, Primary or NOS; Myxedema, Primary or NOS

Overview

Hypothyroidism is the underproduction of hormones by a gland in the neck called the thyroid gland, which is located in the front of the neck, near the "Adam's apple." Its function is to produce hormones (thyroid hormones) that are responsible for regulating the body's metabolism. When the thyroid does not produce sufficient levels of thyroid hormones, many body systems are affected. The body systems essentially slow down.

There are several causes of hypothyroidism. This condition can result when the thyroid gland itself becomes damaged or diseased (e.g., Hashimoto's thyroiditis), which is the most common cause; after surgical removal of the thyroid; or after treatment of an overactive thyroid (hyperthyroidism). Hypothyroidism can also result when another hormone-producing gland (the pituitary gland) or a part of the brain (hypothalamus) fails to stimulate the activity of the thyroid. Sometimes, hypothyroidism is due to a lack of iodine in the diet, although this has become increasingly rare with the availability of iodine-supplemented salt (iodized salt). Autoimmune diseases may be associated with hypothyroidism such as celiac disease.

Incidence and Prevalence: Hypothyroidism is the most common type of thyroid disorder, far more common than overactive thyroid (hyperthyroidism).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Risk factors for hypothyroidism include obesity and thyroid surgery. This disease affects women 3 to 4 times more often than men ("Hypothyroidism"). It can occur at any age but typically strikes as one gets older. Those over 50 years of age are more at risk (Rennert).

Source: Medical Disability Advisor



Diagnosis

History: Individuals may complain of fatigue and sluggishness despite increased sleep time, intolerance to cold, impaired memory and concentration, weight gain, hoarseness, facial swelling (edema), depression, and constipation. Women may report heavier than normal menstrual flow. In mild cases, symptoms may not be noticed.

Physical exam: The exam may reveal swelling of the legs and face (particularly the area around the eyes) due to fluid accumulation (edema). The skin may be coarse and dry and may feel cool to the touch. The body temperature may be low. Hair may be unusually dry or thin. Reflexes may be sluggish. The thyroid gland may or may not feel enlarged. The heart rate may be low (bradycardia).

Tests: A high blood level of thyroid-stimulating hormone (TSH) and a low level of thyroid hormone indicates hypothyroidism. Blood tests may also show associated abnormalities of liver or kidney function, as well as elevated cholesterol levels. For pituitary and hypothalamic hypothyroidism, thyroxine (T4) (hormone produced in thyroid gland that affects metabolic rate) and thyroid stimulation hormone (TSH) (hormone that controls release of thyroid hormone) levels will be low.

Source: Medical Disability Advisor



Treatment

Hypothyroidism is treated with thyroid hormone replacement medication. A cortisol level should be obtained prior to starting with thyroid hormone therapy to make sure treatment does not precipitate an adrenal crisis (a life-threatening situation). Routine monitoring of thyroid hormone levels is necessary, and adjustments to the medication dose may be required periodically. Because the cause of thyroid failure is likely to be progressive and permanent, hormone replacement medications are usually taken for the rest of the individual's life.

In cases in which hypothyroidism is caused by another disease, treatment of that disease may lessen or eliminate the symptoms of hypothyroidism.

Source: Medical Disability Advisor



Prognosis

With treatment, the prognosis is excellent. Hypothyroidism is readily cured with hormone replacement therapy, and there are usually no long-term adverse effects. But hypothyroidism can recur if individuals stop hormone replacement therapy without medical supervision. If hypothyroidism is not treated, it can progress to coma and possibly death.

Source: Medical Disability Advisor



Complications

Individuals with hypothyroidism are at a greater risk for high cholesterol (hypercholesterolemia), hardening of the arteries (arteriosclerosis), and subsequent heart disease. Medications characterized as depressants (such as certain painkillers, general anesthesia, or opiates) and alcoholic beverages may have an unusually pronounced effect. Emotional depression is commonly seen. Some individuals develop paranoia. Increased susceptibility to infections, extreme dilation of the colon (megacolon), and infertility can also result.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Individuals with mild hypothyroidism will not need work restrictions or accommodations. Accommodations depend on the type and severity of symptoms, as well as the individual's job requirements. Working outdoors in cold weather may be unbearable, requiring reassignment to an indoor position. Fatigue may make strenuous work difficult or impossible, making transfer to a more sedentary position necessary. These symptoms, if due to hypothyroidism, should disappear within 3 months of normalization of thyroid blood tests.

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:

  • Does individual complain of fatigue and sluggishness despite increased sleep time? Does individual have an intolerance to cold or impaired memory or concentration?
  • Does individual report weight gain, hoarseness, facial edema, depression, and constipation?
  • If female, does individual report heavier than normal menstrual flow?
  • On physical exam, does individual have edema of the legs and face (particularly the area around the eyes)?
  • Is skin coarse and dry and cool to the touch? Is body temperature low?
  • Is individual's hair unusually dry or thin? Are reflexes sluggish?
  • Is thyroid gland palpable? Does individual have bradycardia?
  • Has individual had complete blood thyroid testing done?
  • Were liver and kidney functions tests done? Blood cholesterol?
  • Have conditions with similar symptoms been ruled out?

Regarding treatment:

  • Is individual being treated with thyroid hormone replacement medication?
  • Does individual see a physician regularly to monitor the condition?
  • If there is an underlying condition, is it being treated?

Regarding prognosis:

  • Does individual have any conditions that may affect the ability to recover?
  • Does individual have any complications such as hypercholesterolemia, arteriosclerosis, and subsequent heart disease? Does individual have an unusually pronounced effect from depressant medications and alcoholic beverages? Does individual have emotional depression or paranoia? Does individual have increased susceptibility to infections, megacolon, or infertility?

Source: Medical Disability Advisor



References

Cited

"Hypothyroidism." WebMD.com. 14 Nov. 2002. WebMD, LLC. 2 Nov. 2004 <http://my.webmd.com/hw/health_guide_atoz/aa34957.asp>.

Rennert, Nancy J. "Hypothyroidism." MedlinePlus. 19 Apr. 2004. National Library of Medicine. 2 Nov. 2004 <http://www.nlm.nih.gov/medlineplus/ency/article/000353.htm#Causes,%20incidence,%20and%20risk%20factors>.

Source: Medical Disability Advisor






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