Psoriasis is a chronic autoimmune condition in which the immune system causes the overproduction of skin cells—they’re produced in days, rather than weeks. This can result in thick, scaly patches forming on the skin, often with intense itching. The different types of psoriasis include plaque psoriasis, scalp psoriasis, guttate psoriasis, inverse psoriasis, pustular psoriasis, and erythrodermic psoriasis. Psoriasis can’t be cured; most people who have psoriasis have it for life. But it can be treated, and people with psoriasis can develop healthy lifestyle habits to minimize the condition, such as avoiding triggers like stress, smoking, and alcohol. Between 10% and 30% of people with psoriasis develop psoriatic arthritis, in which joint pain, stiffness, and swelling accompany scaly patches of skin.