Main causes of pain and swelling
Injuries/Trauma: Due to a fall, blow, bruise, or injury to the muscles and ligaments (for example, sprain/strain), the blood flow to the area increases, causing swelling and pain.
Infection: Bacterial infections (for example, cellulitis) can cause the area to become red and swollen and feel very painful. It can feel warm to the touch.
Arthritis: Inflammation in the joints can cause pain and swelling (for example, rheumatoid arthritis).
Allergy: When an insect bites or comes into contact with an allergen, the area can suddenly swell and feel painful or itchy.
Poor Circulation: Venous insufficiency can cause swelling and pain in the legs.
Overuse: Continuous overuse of the same muscle or joint (e.g., strenuous exercise) can cause swelling in that area.
