Vascular malformations are abnormalities of the veins, arteries, capillaries and lymphatics. Often these malformations have combinations of veins and lymphatics. These blood vessels may be larger, more fragile and more numerous than normal. These anomalies can result in changes in the blood flow which can be painful or result in blood clots. Often these blood vessels are more fragile than normal and are so easily injured and can bleed and bruise.
Capillary malformations are known as port wine stains and are caused by the smallest blood vessels or capillaries failing to constrict. Lymphatic malformations involve abnormalities of the lymph system and are often known as lymphangiomas. They can present as a small swelling or a much larger swollen or raised area and can result in skin changes, repeated infections or bleeding.
Venous malformations may be present in the skin or occur in any type of tissue such as the muscles or mucous membranes. They can be visible through the skin, but often they aren’t physically visible and can present as swelling or bruising after there has been increased blood flow to the affected area, for example, after exercise, when crying or becoming upset. Vascular malformations often grow a bit faster when there are hormonal changes such as during puberty or pregnancy.
Congenital venous malformations occur due to a genetic mutation during foetal development and typically aren’t inherited.