What Are the Causes of Extreme Fatigue & Weakness?

Fatigue and weakness are terms that describe two sensations, but are often used by patients interchangeably. Both terms indicate symptoms that may be related to underlying medical causes, or may be caused by certain lifestyles.

Considerations

• Generalized fatigue and weakness may occur with too much activity to which you're not accustomed. According to WebMD, extreme weakness could indicate problems with the thyroid gland, a nerve disorder such as Guillain-Barre syndrome or myasthenia gravis.

More Considerations

• Fatigue may be caused by an illness, such as the flu, or by lack of exercise. Mild fatigue generally does not require medical intervention. Extreme or prolonged fatigue that does not go away within a few weeks should be evaluated by your health care provider.

Speculation

• According to MedlinePlus, illnesses such as Addison's disease, anorexia, arthritis, cancer, congestive heart failure, diabetes and kidney disease can cause extreme fatigue and weakness. Seek immediate medical care if the onset is sudden.

Possibilities

• Mayo Clinic includes anemia, chronic fatigue syndrome, COPD, sleep apnea, restless leg syndrome and inactivity as possible causes of extreme fatigue and weakness. Only a trained health care provider is qualified to determine the root cause of fatigue.

More Tests

• Since fatigue and weakness are often used interchangeably by patients, your health care provider will likely do a complete history and physical to determine the origin of the symptoms. This may include an EKG to look for heart abnormalities and lab tests for functions of liver, thyroid and enzymes, along with tests for infection.