Muscle Swelling

Overview

Muscle swelling, or muscle edema, occurs when excess fluid accumulates in muscle tissue or surrounding areas. This can result from injury, inflammation, infection, or various medical conditions. The swelling may be localized to one muscle group or affect multiple areas of the body.

Common Causes

Injury-Related

  • Muscle strain or tear: Overstretching or rupture of muscle fibers
  • Contusion (bruise): Direct blow causing bleeding in muscle
  • Overuse injury: Repetitive stress on muscles
  • Compartment syndrome: Pressure buildup in muscle compartment
  • Rhabdomyolysis: Severe muscle breakdown

Inflammatory Conditions

  • Polymyositis: Autoimmune muscle inflammation
  • Dermatomyositis: Muscle and skin inflammation
  • Inclusion body myositis: Progressive muscle inflammation
  • Viral myositis: Muscle inflammation from viral infection
  • Bacterial myositis: Bacterial infection of muscle

Systemic Conditions

  • Deep vein thrombosis (DVT): Blood clot causing leg swelling
  • Heart failure: Fluid retention in extremities
  • Kidney disease: Impaired fluid regulation
  • Liver disease: Decreased protein production
  • Hypothyroidism: Can cause muscle swelling
  • Medications: Statins, corticosteroids, others

Other Causes

  • Electrolyte imbalances: Sodium, potassium disturbances
  • Allergic reactions: Angioedema affecting muscles
  • Lymphedema: Lymphatic system dysfunction
  • Tumors: Muscle tumors or nearby masses
  • Parasitic infections: Trichinosis, toxoplasmosis

Associated Symptoms

  • Pain or tenderness in affected muscle
  • Warmth and redness over swollen area
  • Muscle weakness or difficulty moving
  • Muscle stiffness or tightness
  • Visible enlargement of muscle
  • Skin tightness or shininess
  • Fever (with infection)
  • Dark urine (with rhabdomyolysis)
  • Fatigue and malaise
  • Joint pain or swelling

Diagnosis

  • Physical examination: Assessment of swelling and function
  • Blood tests: CK levels, inflammatory markers, electrolytes
  • Imaging: Ultrasound, MRI, or CT scan
  • Electromyography (EMG): Muscle electrical activity
  • Muscle biopsy: For suspected myositis
  • Doppler ultrasound: To rule out blood clots
  • Compartment pressure testing: If compartment syndrome suspected

Treatment Options

Immediate Care

  • RICE protocol: Rest, Ice, Compression, Elevation
  • Anti-inflammatory medications: NSAIDs for pain and swelling
  • Gentle stretching: Once acute phase passes
  • Hydration: Especially important for rhabdomyolysis

Medical Treatments

  • Corticosteroids: For inflammatory myositis
  • Immunosuppressants: For autoimmune conditions
  • Antibiotics: For bacterial infections
  • Diuretics: For fluid retention
  • Physical therapy: Restore function and strength
  • Surgery: For compartment syndrome or severe injury

When to Seek Emergency Care

Seek immediate medical attention for:

  • Severe, sudden muscle pain and swelling
  • Inability to move the affected muscle
  • Numbness or tingling below the swelling
  • Skin that feels tight and shiny
  • Dark or tea-colored urine
  • Signs of infection (fever, red streaks)
  • Chest pain or difficulty breathing
  • Rapid swelling after injury

See Your Doctor If:

  • Swelling persists more than a few days
  • Multiple muscle groups affected
  • Recurring episodes of swelling
  • Associated with new medication
  • Progressive muscle weakness
  • Unexplained muscle swelling