Infections - infections, like a cold or flu, can activate the immune system and trigger a flare.
Stress - flares are common after either emotional or physical trauma (surgery, accidents, emotional distress).
Pregnancy - flares are common during the pregnancy as well as during the period directly after the birth of a baby.
Sunlight - for those who suffer a side effect of photo sensitivity, this is more common.
Starting or stopping a new drug - certain drugs and herbal supplements have been show to trigger lupus flares. Before starting or stopping any drug or supplement, consult your doctor.