Cold sores
Cold sores are small blisters that develop on the lips or around the mouth. They are caused by the herpes simplex virus 1 (HSV1) and often start with a tingling, itching or burning sensation around your mouth, which later develops into fluid-filled sores, particularly on the edges of the lower lip. It can be triggered by various factors such as stress, cold, fever, low immunity and menstruation. The supplement Lysine, an amino acid, can suppress the virus.