Psoriatic arthritis is a chronic inflammatory arthritis associated with psoriasis, caused by an overactive immune system. It leads to joint pain, stiffness, and swelling, commonly affecting the hands, feet, knees, and spine, and may also involve enthesitis (inflammation where tendons attach to bone). Symptoms are often asymmetric, with morning stiffness lasting 30 minutes or longer, and may include diffuse swelling of entire fingers or toes (dactylitis). Nail changes such as pitting or separation from the nail bed are common. Early diagnosis and treatment are important to reduce inflammation and prevent permanent joint damage.