Intermittent claudication is the medical term for pain, numbness, burning, heaviness or cramping in the legs that occurs during activities such as walking or climbing stairs. You may feel these symptoms in any of your lower limb muscles, including those in the feet, calves, thighs, or buttocks. Intermittent claudication may be localized or diffuse, affecting one or both legs. Intermittent claudication is primarily caused by peripheral artery disease, also called peripheral vascular disease. In this condition, your muscles cannot get enough oxygen because blood circulation has been blocked or restricted in the arteries.