What causes weakness and fatigue in the upper limbs?

Generally, upper limb weakness and fatigue may be caused by overexertion, insufficient sleep, lack of exercise, polymyositis, cervical spondylosis, and other factors. Symptomatic management through general treatments and medication may be required. If symptoms persist, it is recommended to seek medical attention promptly and undergo appropriate treatment under a doctor's guidance. A detailed explanation is as follows:

1. Overexertion

Excessive physical strain can lead to excessive energy consumption in muscle tissues, producing metabolic byproducts such as lactic acid, which may cause muscle fatigue and a feeling of weakness. This may be accompanied by symptoms such as muscle soreness and stiffness. It is recommended to ensure adequate rest and avoid overexertion to relieve muscle fatigue.

2. Insufficient Sleep

Lack of sleep can impair the body's recovery and repair processes, leading to fatigue in the muscles and nervous system. It is often accompanied by symptoms such as lethargy, difficulty concentrating, and memory decline. It is recommended to adjust sleep schedules and ensure sufficient sleep duration.

3. Lack of Exercise

Insufficient physical activity can lead to gradual loss of muscle tissue, thinning of muscle fibers, and reduced muscle strength. When performing daily activities or light physical labor, muscles may not respond effectively, leading to fatigue. It is recommended to engage in regular moderate physical exercise, such as walking, swimming, or light weightlifting, to enhance muscle strength and endurance.

4. Polymyositis

Polymyositis is an autoimmune disease in which the immune system mistakenly attacks the body's own muscle tissues, causing muscle inflammation and damage. The upper limb muscles, being frequently used, are more susceptible to involvement, leading to symptoms such as weakness and fatigue. It may be accompanied by muscle pain, joint pain, and rashes. It is recommended to follow a doctor's guidance in using medications such as cyclophosphamide tablets, methotrexate tablets, and prednisone acetate tablets for treatment.

5. Cervical Spondylosis

Chronic strain and degeneration of the cervical spine may lead to cervical spondylosis. In such cases, herniated discs or bone spurs may compress nerve roots, interfering with normal nerve signal transmission. Weakened nerve signals reaching the upper limb muscles can result in reduced muscle strength and easy fatigue. Symptoms may also include neck pain, arm numbness, and finger weakness. It is recommended to follow a doctor's guidance in using medications such as chlorzoxazone tablets, eperisone hydrochloride tablets, and sodium naproxen tablets for treatment.

It is recommended to consume more protein-, vitamin-, and mineral-rich foods in daily life, such as lean meat, fish, vegetables, and fruits, to provide adequate nutrition for muscles, enhance muscle function, and alleviate symptoms of weakness.