Muscle Strain: This is the most common cause of sharp, burning pain in the calf after exertion, such as walking. Muscle strains occur when the muscle fibers are stretched or torn, leading to pain, swelling, and limited mobility.

Shin Splints (Medial Tibial Stress Syndrome): Although shin splints typically affect the medial aspect of the lower leg, they can also occur on the lateral side. The condition is characterized by pain and swelling due to inflammation of the muscles, tendons, and bone tissue.
Peroneal Tendinopathy: Inflammation or degeneration of the peroneal tendons, which run along the lateral aspect of the calf, can cause sharp, burning pain, especially after activities like walking.
Calf Vein Thrombosis: While less common than other causes, a blood clot in the veins of the calf can cause swelling, pain, and warmth, especially after exertion.

Deep Vein Thrombosis (DVT): A blood clot in the deep veins of the leg can be life-threatening if it breaks loose and travels to the lungs (pulmonary embolism). Symptoms can include swelling, pain, and warmth, making it crucial not to miss this diagnosis.
Compartment Syndrome: This is a serious condition where increased pressure within a muscle compartment can lead to muscle and nerve damage. It typically presents with severe pain, especially on exertion, swelling, and sometimes paresthesia.

Popliteal Artery Entrapment Syndrome: A rare condition where the popliteal artery is compressed, leading to pain, swelling, and potentially severe complications like ischemia.
Stress Fracture: Although more common in the bones of the foot or the tibia, stress fractures can occur in the fibula (the bone on the lateral side of the lower leg), causing pain that worsens with activity.
Nerve Entrapment (e.g., Peroneal Nerve Compression): Compression of the peroneal nerve can cause pain, numbness, and weakness in the lateral aspect of the leg and foot.