Weakness

Definition:
Weakness is a reduction in the strength of one or more muscles.

Alternative Names:
Lack of strength; Muscle weakness

Considerations:
Weakness may be subjective (the person feels weak, but has no measurable loss of strength) or objective (measurable loss of strength as noted in a physical exam). Weakness may be generalized (total body weakness) or localized to a specific area, side of the body, limb, or muscle.

A subjective feeling of weakness may be associated with infectious diseases such as infectious mononucleosis and influenza.

Weakness is more notable when it occurs in only one area of the body (localized or focal weakness). Localized weakness may follow a stroke, exacerbation of multiple sclerosis, or trauma to a motor nerve root or peripheral nerve.

Common Causes:
Measurable weakness may result from a variety of conditions including metabolic, neurologic, primary muscular diseases, and toxic disorders.
METABOLIC NEUROLOGIC PRIMARY MUSCULAR DISEASES TOXIC OTHER
  • Myasthenia gravis (an autoimmune disorder that interferes with the transmission of nerve impulses to muscle)
  • Poliomyelitis (an infectious disease that damages motor neurons)
  • Dermatomyositis/polymyositis (autoimmune diseases leading to proximal muscle weakness, muscle pain, and sometimes skin rashes)


Home Care:
Follow prescribed therapy for treating the underlying cause of the weakness.

Call your health care provider if:
  • There is weakness confined to one area of the body.
  • There is prolonged, unexplained weakness.
  • You notice the sudden onset of weakness, particularly when it is localized and not accompanied by other complaints, such as fever.
  • You become suddenly quite weak following a typical viral illness.


What to expect at your health care provider's office:
The medical history will be obtained and a physical examination performed.

Medical history questions documenting the weakness in detail may include:
  • Time pattern
    • When did the weakness begin?
    • Did it begin with an illness or injury?
    • Did it occur suddenly or gradually?
    • Is the weakness worse in the morning or at night?
    • Is the weakness noticed only after strenuous activity or exercise?
    • Did it start following a typical viral illness, such as a cold?
    • Did it start after a vaccination?
  • Quality
    • Is the weakness constant or does it come and go, sometimes effecting different parts of your body?
    • Does the weakness affect breathing?
    • Does it affect talking, chewing, or swallowing?
    • Does it affect walking, climbing stairs, sitting, getting up?
    • Does it affect use of the hands, arms, or shoulders?
    • Is there pain with the weakness?
    • Is there numbness or tingling with the weakness?
  • Location
    • Is the weakness limited to a specific area?
    • Has the area of weakness increased or decreased?
  • Aggravating factors
  • Relieving factors
    • Does anything help relieve the weakness?
      • Rest
      • Eating
      • Pain relief
  • Other symptoms
  • Additional important information
    • What medications are being taken?
    • Are there any known allergies?
Physical examination may include special attention paid to examination of heart, lungs, and thyroid gland. If there is localized weakness, the examination will focus on the nerve and muscle functions.

Diagnostic tests that may be performed include: After seeing your health care provider:
You may want to add a diagnosis related to weakness to your personal medical record.


Review Date: 11/2/2001
Reviewed By: Sarah Pressman Lovinger, M.D., General Internist at Boston Medical Center, Boston, MA. Review provided by VeriMed Healthcare Network.

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