Differential Diagnosis for Bilateral Upper and Lower Leg Pain

Single Most Likely Diagnosis

• Muscle Strain or Overuse: This is the most likely diagnosis given the symptoms of achiness in the legs that improve with stretching. Muscle strain or overuse can occur from repetitive activities or sudden increases in physical exertion without proper warm-up or cool-down stretches.

Other Likely Diagnoses

• Shin Splints (Medial Tibial Stress Syndrome): Characterized by pain in the lower legs, shin splints are common in runners or individuals who have recently increased their physical activity. The pain typically improves with rest and stretching.
• Compartment Syndrome (Chronic): Although more commonly associated with acute pain, chronic compartment syndrome can cause leg pain that improves with stretching. It's due to increased pressure within the muscle compartments.
• Peripheral Artery Disease (PAD): While PAD typically presents with intermittent claudication (pain in the legs when walking that stops when resting), some patients might experience pain at rest or achiness that could potentially improve with stretching due to increased blood flow.

Do Not Miss Diagnoses

• Deep Vein Thrombosis (DVT): Although DVT usually presents with unilateral leg swelling, warmth, and pain, it's crucial not to miss this diagnosis due to its potential for pulmonary embolism. Bilateral DVT, though less common, could present with bilateral leg pain.
• Osteomyelitis or Septic Arthritis: Infections of the bone or joint can cause severe pain, and while they might not typically improve with stretching, it's essential to consider these diagnoses to prevent serious complications.
• Neoplastic Processes: Rarely, leg pain can be a symptom of a neoplastic process affecting the bones, such as multiple myeloma or metastatic disease.

Rare Diagnoses

• Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. Some types can lead to joint hypermobility and musculoskeletal pain.
• Stickler Syndrome: A genetic disorder that can cause musculoskeletal pain among other symptoms like eye and hearing problems.
• Fibromyalgia: While not typically causing bilateral leg pain in isolation, fibromyalgia is a condition characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory, and mood issues.