Heart and Vascular
Venous Malformation (VM)
Our team of vascular specialists offer the latest nonsurgical and surgical treatments to protect your child’s health.
Medically reviewed by Misty Humphries, M.D. on March 18, 2026.
Care for Your Child’s Well-Being
Specialists at UC Davis Vascular Center offer advanced procedures to treat vascular malformations. We provide compassionate heart and vascular care that protects your child’s health while helping to improve their appearance and well-being.
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What Is a Venous Malformation (VM)?
A VM occurs when veins don’t form as they should while your baby is in the womb. The condition is present at birth (congenital).
Veins carry oxygen-poor blood to your baby’s heart. With VM, the affected veins may be misshapen or enlarged. The abnormal veins often form in clusters, causing what looks like a deep blue, purple or red birthmark or bruise. The veins tend to get bigger as your child grows.
VMs are the most common congenital vascular malformation. They can form anywhere in your child’s body. One type, called blue rubber bleb nevus syndrome, or Bean syndrome, causes venous malformations in the mouth, stomach and intestines.
Blood can pool in the affected veins, causing bleeding and pain. Blood clots can form deep in a vein, causing a potentially life-threatening deep vein thrombosis, pulmonary embolism or stroke.
Symptoms of Venous Malformation
VMs are present at birth. However, they may not be noticeable right away. VMs can form in multiple parts of your child’s body. They can affect shallow veins under the skin surface or veins deep in the body, such as in the intestines. Symptoms depend on the location and size of the lesion.
Common Symptoms
A venous malformation may look like:
- Deep blue, purple or red birthmark or bruise
- Lesions that get bigger or darker when a child is active, cries or lies down
- Lesions that get lighter and feel soft when you press on the skin
- Raised blue, purple or red veins under the skin
Emergency Symptoms
A VM that causes a blood clot is a medical emergency. You should seek immediate medical care for these symptoms:
- Chest pain
- Difficulty speaking or breathing
- Dizziness or fainting
- Facial drooping
- Fast heartbeat
- Limb weakness or paralysis
- Severe swelling, pain or bleeding at the lesion site
Venous Malformation Causes
A gene change (mutation) affects how veins form while a baby is in the womb. In most cases, this gene change occurs for no known reason. Less commonly, a child inherits a gene change from a parent that causes VMs. The condition affects members of the same family.
Diagnosis and Testing for Venous Malformation
Specialists at UC Davis Vascular Center perform advanced medical imaging tests to diagnose and manage VMs. Test findings help our team customize the right treatment plan for your child.
Angiogram
An angiogram uses an injectable dye and imaging to show blood as it moves through blood vessels. Your child may get an X-ray angiogram, CT angiogram (CTA), magnetic resonance angiogram (MRA) or magnetic resonance venogram (MRV).
MRI
An MRI shows the location and size of the lesion, as well as surrounding blood vessels, nerves and other important structures.
Other Imaging Tests
An ultrasound can show blood flow through veins. Less commonly, a child may get a CT scan to see if a lesion affects bones.
Venous Malformation Treatments
VM treatments depend on disease severity, symptoms and other factors. Small or mild VMs may not need treatment. We monitor your child’s veins for signs of growth or other issues. At the UC Davis Vascular Center, our specialists work with your family to ensure your child has the best outcome.
Compression Garments
Compression garments can ease pain and swelling caused by VMs in your child’s arms or legs.
Embolization
A vascular specialist threads a thin tube (catheter) into the blood vessels that feed the malformation and injects material to block blood flow, reducing its size before surgery or other treatment.
Laser Therapy
Laser treatments can shrink the affected veins and stop blood flow.
Medications
Nonsteroidal anti-inflammatory drugs (NSAIDs) can ease pain and swelling for your child. Some children may need medications to lower the risk of blood clots.
Sclerotherapy
A vascular specialist injects a chemical solution into the affected veins. The solution causes scarring inside the vein, closing it off to blood flow.
Vascular Surgery
A vascular surgeon ties off the affected veins, stopping blood flow. In some cases, the surgeon removes some of the enlarged veins and uses other treatments on the remaining veins.
“Venous malformations: clinical diagnosis and treatment,” NIH National Library of Medicine, https://pmc.ncbi.nlm.nih.gov/articles/PMC5220204/
Who does it affect?
2 in 10KPeople have venous malformations.
Source: Cardiovascular Diagnosis and Therapy: Venous Malformations: Clinical Diagnosis and Treatment
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