It's smart to ask about potential risks before any procedure. Laser treatment for spider veins is generally considered safe when performed by a qualified professional, but like any medical treatment, it does carry some potential side effects. The most common are temporary redness, mild swelling, or bruising in the treated area, which typically resolve within a few days. Some people experience temporary darkening of the skin, though this usually fades over time. There's a small risk of blistering or scarring if the laser settings aren't appropriate for your skin type, which is why it's crucial to go to someone experienced. Rarely, people might experience changes in skin pigmentation that can be more persistent. During your consultation, a good practitioner should assess your skin type, discuss your medical history, and explain any specific risks that might apply to you. If you have certain conditions like active infections or are pregnant, the treatment might not be recommended.