Why do I keep getting cold sores on my lip?

Viruses cause sores. We all harbor the viruses that cause cold sores. When our immune system is compromised these cold sores will continue to return. Getting a good nights sleep, a good well balanced diet and coping better with daily stress can go a long way to improving the health of your immune system. If your sores persist, please see your physician.
It's viral. . . . Cold sores on the outside of the lip are usually viral and the virus lives in the nerve of the affected side. There are triggers that bring them about, such as sunlight, citrus fruits, stress and trauma. Find out which trigger is making them happen and you may be able to treat it more effectively. Creams or medication are both effective; just treat it when it is tingly to be most effective.
Nature of disease. Cold sores are caused by the herpes simplex virus and are recurrent by nature. They are not predictable and always frustrating. If they ocurr frequently enough it might makes sense to take a daily medication to suppress them.
Chronic Carrier. If you keep getting cold sores (herpes simplex virus), you will likely benefit from daily suppressive therapy. This is usually done for a period of 6 months to one year before taking a break to see if you stay clear.