Differential Diagnosis for Muscle Pain

• Single Most Likely Diagnosis
  • Muscle Strain: This is the most common cause of muscle pain, often resulting from overuse, injury, or excessive physical activity. The pain is typically localized to the affected muscle and may be accompanied by swelling, bruising, or limited mobility.
• Other Likely Diagnoses
  • Fibromyalgia: A chronic condition characterized by widespread muscle pain, fatigue, and tender points. It's often associated with sleep disturbances, anxiety, and depression.
  • Overuse or Repetitive Strain Injury: Similar to muscle strain but occurs due to repetitive movements or activities that lead to muscle fatigue and pain.
  • Viral Myositis: Muscle inflammation caused by viral infections, which can lead to muscle pain, weakness, and fever.
  • Medication Side Effects: Certain medications, such as statins, can cause muscle pain as a side effect.
• Do Not Miss Diagnoses
  • Compartment Syndrome: A serious condition where increased pressure within a muscle compartment leads to nerve and muscle damage. It requires immediate medical attention.
  • Rhabdomyolysis: A life-threatening condition where muscle tissue breaks down, releasing myoglobin into the bloodstream, which can cause kidney failure.
  • Polymyalgia Rheumatica: An inflammatory condition that causes muscle pain and stiffness, particularly in the shoulders and hips, and can be associated with giant cell arteritis.
  • Lyme Disease: A bacterial infection transmitted by ticks, which can cause muscle pain, fever, and a distinctive rash.
• Rare Diagnoses
  • Dermatomyositis: A rare inflammatory disease characterized by muscle weakness and skin rash.
  • Polymyositis: A rare inflammatory muscle disease that causes muscle weakness and pain.
  • McArdle Disease: A rare genetic disorder that affects the muscle's ability to break down glycogen, leading to muscle pain and cramping during exercise.
  • Statin-Induced Necrotizing Autoimmune Myopathy: A rare but serious condition where the immune system attacks muscle tissue, often triggered by statin use.