A hickey forms when someone sucks or bites the skin hard enough to break tiny blood vessels just beneath the surface. The pressure creates what’s essentially a bruise, and most hickeys show up on the neck, chest, or inner arm where the skin is thinner and more sensitive. They’re one of the most common minor injuries people rarely think of as injuries at all.
What Happens Under the Skin
When someone applies sustained suction to the skin, the negative pressure pulls blood into the tissue faster than the small blood vessels (capillaries) can handle. Those vessels rupture, and tiny spots of leaked blood called petechiae collect beneath the surface. Enough of these spots clustered together form the dark, visible mark you see as a hickey. It’s the same basic process behind any bruise, just caused by suction instead of impact.
The skin doesn’t need to be broken for this to happen. All the damage occurs underneath, in the layer just below the surface where capillaries sit. Your body treats the pooled blood the same way it treats any bruise: immune cells gradually break down the trapped blood and reabsorb it over time.
How Much Pressure It Takes
There’s no exact threshold that guarantees a hickey, but research on cupping therapy (which uses a similar suction mechanism) offers some useful benchmarks. Suction strong enough to visibly change skin color and cause bruise-like marks generally falls in the range of moderate negative pressure sustained for several seconds to a few minutes. In cupping studies, darker skin discoloration appeared with longer durations of suction, and anything under about 10 seconds of light pressure typically isn’t enough to break capillaries in most people.
In practical terms, a hickey usually requires sustained suction for at least 20 to 30 seconds, though this varies widely depending on the person’s skin and how forcefully the suction is applied. Gentle kissing won’t do it. It takes deliberate, focused pressure in one spot.
Why Some People Bruise More Easily
Not everyone gets hickeys with the same ease, and the difference comes down to a few factors. People who take aspirin or other blood-thinning medications bruise more readily because their blood doesn’t clot as quickly, allowing more blood to leak from damaged capillaries before the body seals them off. The resulting mark tends to be larger and darker than it would be otherwise.
Nutritional deficiencies can also play a role. Low vitamin C, zinc, or certain B vitamins all make the skin and blood vessels more fragile and prone to bruising. Age matters too: as skin thins and loses collagen over the years, capillaries sit closer to the surface with less cushioning, so they rupture more easily under pressure. Lighter skin tones don’t bruise more easily, but hickeys are simply more visible on lighter skin, which creates the impression of greater susceptibility.
Where Hickeys Typically Appear
The neck is the most common location because the skin there is thin, well-supplied with blood vessels, and frequently accessible during intimate moments. The sides of the neck and the area just below the jaw are especially prone. Other common spots include the inner forearm, the chest, the inner thigh, and the shoulders. Any area where skin is soft and capillaries are close to the surface can develop a hickey, but tougher, thicker skin (like the back of the hand or outer forearm) is much more resistant.
How Long They Last
Most hickeys heal within one to two weeks. During that time, you’ll notice the mark shifting through a progression of colors as your body breaks down the trapped blood. It typically starts dark red or purple, then transitions through blue and brown before fading to a greenish-yellow as the last of the blood pigments are reabsorbed. The exact timeline depends on the size and depth of the bruise, your circulation, and how quickly your body clears damaged blood cells.
Smaller hickeys from brief suction may fade in four or five days. Larger, deeper ones from prolonged or aggressive suction can take the full two weeks or occasionally a bit longer.
Speeding Up the Healing Process
In the first day or two, applying something cold to the area helps. A cold compress or ice wrapped in a cloth constricts the blood vessels, limiting further blood leakage and keeping the mark from spreading. Apply it for 10 to 15 minutes at a time with breaks in between.
After the first 48 hours, switching to a warm compress can help speed things along. Warmth dilates blood vessels and improves circulation, which helps your body clear the pooled blood more quickly. Gentle massage over the area may also help disperse the trapped blood, though pressing too hard can irritate the tissue further. Beyond that, there’s no reliable way to make a hickey disappear overnight. Concealer is the most practical short-term solution.
Rare but Real Medical Risks
In extremely rare cases, a hickey on the neck can cause serious harm. A case study published in the New Zealand Medical Journal documented a woman who suffered a stroke after a hickey on her neck damaged her carotid artery, one of the major blood vessels supplying the brain. The suction caused enough trauma to the artery wall to trigger a blood clot, which partially blocked blood flow to the brain.
This is not something most people need to worry about. The handful of documented cases involved hickeys placed directly over the carotid artery with significant force. Still, it’s worth knowing that aggressive suction on the neck carries a small, nonzero risk, particularly for anyone with a clotting disorder or who takes blood-thinning medication. If you ever experience sudden weakness, confusion, difficulty speaking, or severe headache after receiving a hickey on the neck, those are signs of a stroke and require immediate emergency care.