A pimple-like swelling on the upper lip that comes back occasionally may be caused by a blocked oil gland, mild infection, small cyst, or sometimes an early cold sore. Since it is not painful and tends to occur once a year, it is less likely to be a serious problem. In many cases, such swellings settle on their own within a few days. Avoid touching, squeezing, or picking at the area, as this can increase irritation or lead to infection. Keep the area clean, wash your face gently twice daily, and avoid using heavy creams or oily lip products over the swelling. Applying a warm compress for 10-15 minutes a few times a day may help reduce the swelling faster. If the bump becomes painful, filled with pus, increases in size, forms repeated clusters, or does not improve within 1-2 weeks, you should consult a dermatologist for proper examination and treatment. A doctor may prescribe an antibiotic cream, antiviral medicine, or other treatment depending on the exact cause. Maintaining good skin hygiene, staying hydrated, and reducing stress may also help prevent recurrence.