Why do i have lip blisters twice in a two month cycle and i don't feel atleast sick?

Canker/cold sore: Once your body has been infected with the cold sores virus, there is nothing you can do to prevent outbreaks.Stress and illness, particularly the flu and the common cold, increase the likelihood of an outbreak, there is still no definitive answer as to what causes outbreaks. A particular event may trigger an outbreak at one time in your life and fail to to trigger an outbreak another time.

Why should you?: Without knowing what you mean by "lip blisters" there's no clear answer. Most people would assume you mean cold sores which can be brought on by the stress of physical illness but just as often just appear. If that's what you have then they would always occur in the exact same place, are not serious, but if occurring more than once or twice per year can be treated and prevented with medication.

Lip blisters: Lip blisters that develop on the outer part of the lip is often caused by herpes simplex type 1 virus, and is often preceded by a tingling or burning sensation. Certain stresses can cause an outbreak, and excessive sun exposure sometimes also provoke it. Prescription anti-viral meds like Acyclovir and valacyclovir can reduce the duration of the blister. You may have a blister and no other symptom.