17152 Klippel Trenaunay Syndrome Kts
Informed by recognized medical guidance
Overview
Klippel Trenaunay syndrome (KTS) is a rare condition present at birth. It affects blood vessels, skin, and tissue. The main signs are a red birthmark (port-wine stain), widened veins, and overgrowth of one limb, usually a leg.
Key facts
- KTS is present from birth, though signs may become more obvious with age.
- It usually affects only one arm or one leg.
- The cause is a gene change that happens by chance before birth, not inherited from parents.
- Most people with KTS can live active, full lives with good medical care.
No, KTS is rare. Experts estimate it affects about 1 in 100,000 people.
KTS affects both boys and girls equally and can occur in any ethnic group. It is present from birth.
Symptoms
- Sudden severe pain or swelling in the affected limb
- Chest pain or difficulty breathing
- Coughing up blood
- Weakness on one side of the body, trouble speaking, or confusion
- Heavy bleeding from the affected area that does not stop with pressure
- ⚠Bleeding that stops with pressure but comes back
- ⚠Redness, heat, or a fever – these may be signs of infection
- ⚠A swollen, tender, hard vein that is painful to touch (thrombophlebitis)
- ⚠A wound that is getting bigger or not healing
Common symptoms
- Port-wine stain birthmark (a pink, red, or purple mark on the skin)
- Large, bulging veins (varicosities)
- One leg or arm being larger or longer than the other
- Pain, aching, or heaviness in the affected limb
- Swelling, especially at the end of the day
Symptoms in children
- Birthmark visible at birth
- One limb slightly larger than the other
- Small blisters or milky spots on the skin
- Tiny red spots or extra veins under the skin
Symptoms in older adults
- More noticeable overgrowth of the limb
- Chronic swelling (lymphoedema) that does not fully go down
- Skin dryness, ulcers, or sores
- Increased risk of blood clots in the affected veins
Causes
Main causes
- KTS is caused by a change (mutation) in a gene called PIK3CA.
- This gene change happens randomly in some cells as the baby grows in the womb.
- It is not passed from parent to child.
Risk factors
- There are no known risk factors.
- KTS is not caused by anything a parent did or did not do during pregnancy.
When to see a doctor
See a doctor urgently if:
- Bleeding from a birthmark or vein that will not stop
- Sudden, severe pain or swelling in the affected limb
- Chest pain, shortness of breath, or coughing up blood
- Signs of a stroke, such as weakness on one side or trouble speaking
Book a routine appointment if:
- Any birthmark, unusual veins, or difference in limb size – it is best to have it checked
- Worsening pain, swelling, or skin problems in the affected limb
- Questions or concerns about how KTS may affect daily life
Diagnosis
A doctor usually makes the diagnosis by looking at the skin and measuring the limbs, and by checking for the three classic signs: a port-wine stain, widened veins, and overgrowth. They may refer you to a specialist in blood vessels or birthmarks.
Tests that may be done
- Ultrasound – uses sound waves to look at blood flow and veins
- MRI (magnetic resonance imaging) – gives a detailed picture of soft tissue and blood vessels
- X-ray – to measure bone size and length
- Sometimes a small skin sample (biopsy) is taken, but this is not always needed
What to expect at your appointment
The doctor will ask about symptoms and take a family history. They may take photos or measurements to keep track of the birthmark and limb size. No single test is required for every person – the plan depends on your situation.
Treatment
There is no cure for KTS, but many treatments can help manage symptoms, reduce pain, and prevent complications. Care is often provided by a team of specialists, including skin, vascular, and bone experts.
Self-care at home
- Wear compression stockings or sleeves as advised by your specialist or pharmacist
- Elevate the affected limb when resting to help drain fluid
- Take gentle walks or do light exercise to keep blood moving
- Keep the skin clean and moisturized to avoid cracks and sores
Medical treatments
Doctors may prescribe treatments to manage pain, reduce swelling, or help prevent blood clots. Procedures such as sclerotherapy (an injection to close abnormal veins) may be used. These decisions are always made on an individual basis – talk with your specialist about what is best for you.
When is surgery considered?
Surgery may be considered if overgrowth, bleeding, or pain is severe. Examples include removing extra tissue (debulking) or correcting limb length. Surgery is not needed for most people with KTS.
Living with this condition
Most people with KTS live full and independent lives. You may need to pay extra attention to your skin, veins, and limb size. Regular check-ups help you manage changes and avoid complications.
Lifestyle tips
- Wear comfortable shoes that fit the larger foot or limb
- Protect your skin from cuts and scrapes; clean any small wound immediately
- Avoid standing or sitting still for long periods; move around or elevate your limb
- Talk to your doctor before long flights or major surgery, because you may need extra protection against blood clots
Diet and exercise
Eating a healthy, balanced diet supports your overall health. Regular exercise, such as walking or swimming, is usually safe and good for blood flow. A physiotherapist can tailor exercises to your needs.
Mental health and emotional wellbeing
Living with a visible difference or long-term symptoms can affect confidence and mood. It is normal to feel frustrated, worried, or low at times. If these feelings persist or become overwhelming, talk to your doctor. If you ever have thoughts of self-harm, contact a crisis service immediately.
Prevention
KTS cannot be prevented. It is a gene change that happens by chance before birth. Nothing you did caused it.
Vaccines
There is no vaccine for KTS.
Screening programmes
There is no routine screening for KTS. If there is a family history of vascular malformations, a specialist may offer genetic counselling.
Complications
If left untreated
- Blood clots in the affected veins (deep vein thrombosis)
- A clot that travels to the lungs (pulmonary embolism)
- Bleeding that is difficult to stop
- Chronic swelling that leads to skin changes or open sores
- Infection of skin wounds
- Emotional distress related to appearance or daily challenges
Long-term outlook
With good medical care, most people with KTS remain active and healthy. Treatments are constantly improving. Many complications can be prevented. Life expectancy is usually normal. Living with KTS can be challenging, but support and treatment are available.
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Always verify with your doctor
Health guidelines vary by country and region. The information in this article is based on international clinical guidelines but may not reflect the specific guidelines, medications, or practices in your country. Always discuss your health concerns with your own doctor or healthcare provider, and refer to your local national health guidelines where available.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.
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Sources and guidance
This article is educational and is prepared with reference to recognized health information and clinical guidance sources where available. Specific source links may vary by topic.
Last updated: July 31, 2026
Educational note: This information is for education only and is not a diagnosis.
Use it to support, not replace, advice from a licensed clinician.
If symptoms are severe, worsening, or urgent, call your local emergency number or seek emergency care.