Spider veins, medically known as telangiectasias, are small, dilated blood vessels that appear near the surface of the skin. They often look like fine, red, or blue lines or web-like patterns.

Spider veins can be caused by a variety of factors including genetics, hormonal changes (such as pregnancy or menopause), prolonged standing or sitting, obesity, and sun exposure. They can also be associated with certain medical conditions.

Spider veins are usually not harmful to your health but may cause discomfort or be a cosmetic concern. In some cases, they can indicate an underlying circulatory problem, so it's advisable to have them evaluated by a healthcare professional.

Treatment options for spider veins include sclerotherapy (injecting a solution into the vein to make it collapse), laser therapy (using laser light to destroy the vein), and in some cases, surgery. Compression stockings and lifestyle changes can also help prevent spider veins from worsening.

While some risk factors for spider veins, such as genetics, cannot be changed, there are steps you can take to reduce your risk or prevent them from worsening. These include maintaining a healthy weight, exercising regularly, avoiding prolonged sitting or standing, wearing compression stockings if advised, and protecting your skin from the sun.

You should consider seeing a doctor if you experience pain, swelling, or other symptoms associated with spider veins, or if you're concerned about their appearance. A healthcare provider can evaluate your condition, discuss treatment options, and determine if further evaluation is needed to rule out any underlying medical issues.