Yes, kids can get blood clots, though it’s far less common than in adults. The estimated incidence is about 20 cases per 10,000 pediatric hospitalizations, and most occur in children who are already in the hospital for another reason. Blood clots in children are almost always tied to an underlying trigger, whether that’s a medical device, a chronic illness, or a genetic predisposition.
Why Blood Clots Are Different in Children
In adults, blood clots often develop from well-known lifestyle risks: sitting on a long flight, recovering from surgery, or smoking. In children, the picture looks different. The single biggest risk factor is a central venous catheter, a tube placed into a large vein to deliver medication or fluids during hospital stays. These catheters account for 50 to 80 percent of all deep vein clots in children, compared to just 10 percent in adults. That’s why pediatric blood clots are overwhelmingly a hospital-associated problem rather than something that strikes otherwise healthy kids at home.
Beyond catheters, prolonged bed rest, mechanical ventilation, and major surgery all raise the risk by slowing blood flow and shifting the body toward a clot-promoting state.
Medical Conditions That Raise the Risk
Certain childhood illnesses make blood clots more likely. Cancer is one of the most significant. Children undergoing chemotherapy face elevated risk from the treatment itself, from the central lines used to deliver it, and from the immobility that often comes with intensive care. One chemotherapy drug used in leukemia treatment is particularly known for disrupting the body’s natural clot-prevention system.
Inflammatory and autoimmune conditions also play a role. Kawasaki disease, lupus, and sepsis all damage blood vessel walls and push the blood toward excessive clotting. Children with nephrotic syndrome, a kidney condition that causes protein to leak into the urine, lose key proteins that normally keep clotting in check. In adolescents specifically, obesity, sedentary behavior, and oral contraceptive use are emerging risk factors that mirror the adult population more closely.
Inherited Clotting Disorders
Some children carry genetic mutations that make their blood clot more easily than it should. The two most commonly discussed are Factor V Leiden and prothrombin gene mutations, both of which make the clotting cascade harder for the body to regulate. A child with one of these inherited conditions may never develop a clot on their own, but if a second trigger appears (a hospital stay, an infection, immobility) the combination can tip the balance. Rarer inherited deficiencies in natural anticoagulant proteins like antithrombin, protein C, or protein S carry a higher individual risk and sometimes cause clots in early childhood or even infancy.
Pediatric Stroke From Arterial Clots
Blood clots in children don’t only form in veins. Arterial clots can block blood flow to the brain and cause a stroke. Pediatric arterial stroke affects roughly 2.4 per 100,000 children per year, with a fatality rate approaching 4 percent. About half of affected children have an identifiable underlying condition, but in a significant number, no clear cause is found even after thorough testing.
Heart defects are the leading associated condition, present in 31 percent of pediatric stroke cases in one large international study. Recent infection is another major contributor: children with even a minor infection in the preceding month had more than a fourfold increase in stroke risk compared to those without. This was especially true for children under five. Head and neck trauma in the 12 weeks before a stroke was found in 12 percent of cases. Sickle cell disease carries one of the highest stroke risks of any childhood condition. Without preventive treatment, about 11 percent of children with sickle cell anemia will have a stroke by age 20.
Signs to Watch For
Deep vein clots in children typically cause swelling, warmth, redness, and pain in the affected limb. A child might refuse to walk or use the arm where the clot has formed. In one documented case, a five-year-old presented with a painful, swollen calf and simply refused to bear weight on the leg. The affected calf measured three centimeters larger than the other side.
The challenge is that these symptoms overlap with many more common childhood problems. A clot in the leg has been initially mistaken for a hip irritation, and a pulmonary embolism (a clot that travels to the lungs) has been misdiagnosed as pneumonia. Pulmonary embolism in children can cause sudden shortness of breath, chest pain, and rapid heart rate, but some children show no respiratory symptoms at all, making it easy to miss. If your child has swelling or pain in one limb that doesn’t match an obvious injury, especially if they have any of the risk factors above, it warrants prompt medical evaluation.
How Pediatric Blood Clots Are Treated
Treatment centers on blood-thinning medications. For decades, the standard approach involved injectable medications (low-molecular-weight heparins like enoxaparin) that require regular blood tests to confirm the dose is in the right range. Warfarin, a pill-form blood thinner, has also been used in children but comes with significant practical challenges: it requires frequent blood monitoring (one to four times per month), interacts with many foods and other medications, and is only available in tablet form, which is difficult for infants and young children.
The treatment landscape shifted in 2021 when the FDA approved two oral blood thinners, rivaroxaban and dabigatran, for pediatric use. Both had already been approved in Europe the year before. Large clinical trials (EINSTEIN-Jr for rivaroxaban and DIVERSITY for dabigatran) established that these medications are safe and effective in children. They require less monitoring than older options and are available in formulations designed for younger patients, making day-to-day treatment considerably easier for families.
Long-Term Effects After a Clot
Even after a blood clot resolves, some children develop a condition called post-thrombotic syndrome in the affected limb. In a study of 78 children with a history of deep vein clots, 55 percent reported ongoing pain, 49 percent experienced a tired feeling in the limb, and 40 percent reported heaviness. Swelling persisted in 36 percent, and about one in six had skin discoloration. Half of all patients said their endurance was impaired, meaning they had trouble keeping up with physical activities they could handle before.
These symptoms can linger for months or years and affect a child’s ability to participate in sports, play, and daily routines. Early and effective treatment of the initial clot is thought to reduce the likelihood and severity of post-thrombotic syndrome, which is one reason prompt diagnosis matters so much in the pediatric population.