A stroke occurs when the blood supply to a part of the brain is interrupted or reduced, depriving brain tissue of oxygen and nutrients. Brain cells begin to die within minutes. While often associated with older adults, strokes can affect individuals at any age, including those considered young. Understanding the diverse underlying reasons is important for diagnosis and prevention.
Issues with Blood Vessels and the Heart
Problems within the blood vessels themselves often contribute to strokes in younger individuals. One such issue is artery dissection, which involves a tear in the inner lining of an artery supplying the brain, such as the carotid or vertebral arteries. This tear allows blood to clot, which can block the vessel or send fragments to the brain. Dissections can sometimes result from even minor trauma to the neck.
Another condition, fibromuscular dysplasia (FMD), causes abnormal cell growth in artery walls, leading to narrowed or bulging sections. These irregularities can impede blood flow or create areas where clots are more likely to form. Similarly, Moyamoya disease is a rare, progressive cerebrovascular disorder where the carotid arteries, which supply blood to the brain, gradually narrow. The body attempts to compensate by forming fragile vessels, which are prone to bleeding or blockage.
Structural heart abnormalities can also be a source of stroke. A patent foramen ovale (PFO) or an atrial septal defect (ASD) are common congenital conditions. These openings can allow blood clots from the body’s venous system to bypass the lungs and travel directly to the brain, causing a stroke.
Other cardiac conditions, including issues with heart valves, infections of the heart lining like endocarditis, or certain irregular heart rhythms, can lead to the formation of blood clots within the heart chambers. These clots can then dislodge and travel to the brain.
Blood Conditions and Underlying Diseases
Abnormalities in the blood’s composition or systemic diseases can significantly increase stroke risk in young people. Inherited or acquired blood clotting disorders, known as thrombophilias, make the blood more prone to forming clots. Examples include the Factor V Leiden mutation or antiphospholipid syndrome, leading to increased clotting. These conditions can cause clots to form in blood vessels, impeding blood flow to the brain.
Sickle cell disease, a genetic blood disorder, causes red blood cells to become stiff, sticky, and crescent-shaped. These abnormally shaped cells can block small blood vessels, leading to a reduction in oxygen supply to the brain. Such blockages can occur repeatedly, causing cumulative damage over time.
Inflammatory and autoimmune conditions also play a role by affecting blood vessels throughout the body. Diseases like lupus or Behçet’s disease can cause vasculitis, which can damage the vessels or promote clot formation. This systemic inflammation can narrow blood vessels or make them more susceptible to blockages.
Furthermore, rare genetic metabolic disorders can predispose young individuals to stroke. Conditions such as Fabry disease or homocystinuria involve the body’s inability to properly process certain substances, leading to their accumulation and subsequent damage to blood vessel walls. This damage can weaken vessels, making them more prone to blockages or rupture.
External Factors and Specific Triggers
Certain external factors and specific triggers, distinct from inherent structural or blood disorders, can precipitate a stroke in younger individuals. The use of illicit drugs, particularly stimulants like cocaine and amphetamines, is a notable risk. These substances can cause sudden, severe spikes in blood pressure, lead to vasospasm—a narrowing of blood vessels—or directly damage vessel walls.
Migraine with aura, a type of severe headache accompanied by visual or sensory disturbances, has been associated with an elevated stroke risk in some young individuals, particularly young women. While this link is relatively rare, the exact mechanism is thought to involve temporary changes in blood flow within the brain.
Certain infections can also indirectly or directly contribute to stroke development. For instance, viruses like varicella zoster, or bacterial infections leading to meningitis or endocarditis, can induce inflammation or promote clot formation within blood vessels.
The period of pregnancy and the postpartum phase presents a unique set of physiological changes that can increase stroke risk in young women. Hormonal fluctuations, alterations in blood clotting factors, and conditions like preeclampsia can all contribute. These changes can make blood more prone to clotting or place increased stress on blood vessels.
When the Cause Remains Unknown
Despite extensive medical evaluations, a significant proportion of strokes in young people are classified as cryptogenic. This can be a frustrating reality for patients and their families, as identifying a specific cause often guides targeted prevention strategies.
Even when a clear cause is not found, the medical team continues to provide care focused on preventing future strokes. Ongoing research consistently aims to uncover new underlying mechanisms and risk factors for cryptogenic strokes in young individuals. For some, continued monitoring may reveal a subtle condition over time that was not initially apparent.