A hickey, often called a love bite, is medically defined as a superficial bruise resulting from focused suction pressure on the skin. The intense negative pressure causes the smallest blood vessels, the capillaries, to rupture just beneath the surface. This creates a small collection of blood, or hematoma, which appears as the characteristic dark mark. While most hickeys are harmless, serious, life-threatening outcomes are exceedingly rare. These rare complications stem from the injury’s proximity to major blood vessels in the neck.
The Biological Reality of a Hickey
The visible mark of a hickey is the direct result of mechanical trauma to the microvasculature. Capillaries are the smallest and most fragile blood vessels, located close to the skin’s surface. The suction creates a vacuum that pulls the skin and underlying tissue, causing these delicate vessels to break. Blood leaks out of the damaged capillaries and pools in the surrounding connective tissue, forming a localized bruise.
The color changes observed as a hickey heals are a visual timeline of the body’s natural cleanup process. Initially, the mark appears red or dark purple due to blood pooling under the skin. Over days, specialized cells begin breaking down hemoglobin, the protein in red blood cells that carries oxygen. This breakdown converts the pooled blood products into pigments like biliverdin and bilirubin, causing the bruise to transition through shades of green, yellow, and brown before fading.
How a Hickey Could Cause Serious Harm
The mechanism by which a hickey could cause severe damage is through injury to the major arteries in the neck. The carotid arteries, which supply blood to the brain, run along the side of the neck close to the surface. Extreme or prolonged suction, especially when applied vigorously and directly over the artery, can cause trauma to the vessel wall. This trauma can lead to Carotid Artery Dissection (CAD).
Artery walls are composed of three distinct layers. A dissection occurs when a small tear forms in the innermost layer, allowing blood to flow between the inner and outer layers, forcing them apart. This separation can significantly narrow the central channel, or lumen, through which blood flows to the brain. More concerning, the injury site can also become a focal point for the formation of a blood clot, known as thrombosis.
If a blood clot forms at the site of the dissection, it can impede blood flow. A piece of the clot can break off and travel upstream (an embolus). If this embolus travels to the brain, it can block a cerebral artery, interrupting the blood supply to a portion of the brain. This results in an ischemic stroke, or Cerebrovascular Accident. While exceptionally rare, this sequence is the single plausible pathway for a hickey to result in a life-threatening complication, often requiring some underlying vulnerability in the vessel wall.
When to Seek Medical Attention
While the risk of stroke from a hickey is extremely low, it is important to recognize the warning signs of a potential carotid artery complication. Any individual who has received a hickey and subsequently experiences sudden, severe symptoms requires immediate emergency medical attention. The primary concern is the onset of neurological symptoms, which indicate a disruption of blood flow to the brain.
Symptoms requiring immediate evaluation include sudden weakness or paralysis affecting one side of the body (face, arm, or leg). Other red flags are difficulty speaking, slurred speech (aphasia), or sudden confusion. A severe, distinct headache that feels different from any previous headache, sudden vision changes, or an abrupt loss of balance also signal an emergency. Severe and persistent localized pain or swelling in the neck that does not dissipate should prompt a medical visit, as this could be an early sign of dissection.