Stress : Scientists think your immune system may respond to emotional and mental pressures the same way it does to physical problems like injuries and infections.
Smoking: Lighting up can double your risk of getting psoriasis. If you also have a family history of the disease, you're nine times more likely. And smoking makes it harder to get rid of symptoms. It's closely linked with a kind of pustular psoriasis on your palms and soles that's difficult to treat.
Alcohol: Heavy drinkers have a higher risk, especially younger men. Alcohol can make treatments less effective, too.
Hormone changes: The disease often shows up or flares during puberty. Menopause can also trigger it. A pregnant woman's symptoms may get better or even disappear during pregnancy. But after the baby is born, many women have a flare.