What causes swelling and pain in the arm muscles?

Swelling and pain in the arm muscles may be caused by muscle fatigue, muscle strain, carpal tunnel syndrome, tenosynovitis, or cellulitis.

1. Muscle Fatigue

After intense physical exercise, lactic acid may accumulate in the muscles, triggering an inflammatory response in the body, which can lead to symptoms such as soreness and fatigue in the arms. Applying local heat therapy can help improve blood circulation and relieve discomfort.

2. Muscle Strain

If the arm suffers external impact, it may cause bruising and swelling in soft tissues such as muscles and tendons, resulting in symptoms including swollen, red, and painful arm muscles. It is recommended to minimize arm use during recovery. For significant pain, medications such as diclofenac sodium sustained-release tablets, ibuprofen sustained-release capsules, or acetaminophen tablets may be taken under medical guidance to alleviate symptoms.

3. Carpal Tunnel Syndrome

When the carpal tunnel is compressed or when inflammation causes ligament swelling, it may impair hand blood circulation, leading to sensory abnormalities in the arm and hand, such as tingling and numbness. It is advisable to seek medical care and use a wrist support brace to immobilize the joint. Avoid repetitive wrist movements during recovery to help improve symptoms.

4. Tenosynovitis

When tendon sheath tissue becomes inflamed or infected, inflammatory irritation may damage the tendons, causing symptoms such as muscle swelling and pain. If pain is severe, anti-inflammatory and analgesic medications such as ibuprofen sustained-release capsules, enteric-coated aspirin tablets, or diclofenac sodium sustained-release tablets should be taken as directed by a physician to relieve symptoms. In severe cases, timely medical treatment is necessary, possibly involving surgical removal of thickened synovium or fascia to prevent further disease progression.

5. Cellulitis

Following skin or mucous membrane injury or infection by pathogens such as *Staphylococcus aureus* or streptococci, bacteria may invade and multiply in deep skin tissues. When the arm becomes infected, localized symptoms such as swelling, pain, and redness occur. It is recommended to take antibiotics such as roxithromycin capsules, amoxicillin capsules, or cefixime tablets under the guidance of a healthcare professional to suppress infection and relieve symptoms.

During episodes of arm muscle swelling and pain, it's important to maintain healthy lifestyle and dietary habits and avoid strenuous physical activity. If symptoms persist for an extended period, prompt medical evaluation is necessary to identify the underlying cause and receive appropriate treatment.